INTERVIEW with Kori Phillips, Program Officer for LSAT and CTSAS, Part 3: Development of 6.5mm CT

Kori Phillips holds some linked 5.56mm CT ammunition side by side with a belt of 5.56mm brass-cased dummy ammunition at media day at Picatinny Arsenal on May 4, 2015. Image credit: David Vergun, public domain

Not long after SHOT Show, I got the chance to interview Mrs. Kori Phillips, former program officer for the Army’s Lightweight Small Arms Technologies (LSAT) program, and current program officer for the Cased Telescoped Small Arms Systems (CTSAS) program. We talked at length about both programs, the technology they developed, and the state of lightweight ammunition today. The interview, which spans fifty-five questions, will be broken up into three sections, each covering questions about different aspects of the program, to be published monthly once each in March, April, and May-wait, hold on,

Our Dear Leader Steve has approved a weekly timeline for the interview, instead of a monthly one. That means we’ll be finishing up today! Hooray!

If you haven’t seen the previous two installments, you can read them here and here.

Before we begin, I would like to take a moment to thank Kori and Frank for taking the time to speak with me. They were very patient with me and did not hesitate to answer any of my questions.

Now, we’ve got a lot to get through! My questions are labeled with a bold “TFB“, while Kori’s answers are labeled with a bold “KP“:


TFB: Can you tell me about the caliber study that you did?

KP: We had this notion that there had to be a better bullet out there. And I know that the Army is undertaking a huge project, but it’s not just about the bullet, it’s about the weapon and how you use it and how many rounds of ammunition you are carrying. We stopped at a very simple answer, we had been talking to the AMU, specifically Troy Lawton, and he had an idea for a better bullet. For CT, which isn’t constrained by old weapon configurations, why are we shooting old bullets? Why not use something that shoots better? So it was very quick, only took about six months. We looked at different shapes, different sizes and weight. It came down to the maximum amount of range and effect you could get out of a bullet at the minimum weight. We were looking at where those two lines on the graph crossed, and that’s where we wanted to be. It was very complicated, it was like a four dimensional matrix. It became very obvious early on that the long, low-drag bullet was going to address a lot of the questions we had. You get this range automatically, you don’t need to make it fly faster, or make it heavier, it automatically flies further because it has low drag. And we thought if we could amp up the velocity a little bit, so we can give it more punch. The advantage we have is that we can design a cartridge case around the bullet, we don’t have to try to fit the bullet into an existing cartridge case. I always caveat our caliber study that this is only for cased telescoped.


TFB: Originally, LSAT focused on a 5.56mm weapon, but now the focus with CTSAS appears to be a 6.5mm weapon. How did this change come about? Was it a decision from the Infantry School, or an internal development by CTSAS? Is the 6.5mm now the focus of CTSAS, or a side project?

KP: Based on the success of the original 5.56mm CT system, we were given funding from the Army to pursue a Medium Machine Gun (typically 7.62mm) and a Carbine. The 6.5mm ammunition came about as a result of an optimization study that was done strictly for the CT configuration. Both new weapon systems can be used with either a 7.62mm CT cartridge or the 6.5mm CT cartridge.


Original caption: “Kori Phillips, an ARDEC systems management engineer, talks to Sgt. Jason Reed about the chamber of the lighter version of the M249 machine gun.” Image credit: Eric Kowal, RDECOM. Public domain.


TFB: Fort Benning appears to have issued a 1,200m effective range requirement (this appears on some slides in NDIA presentations). What can you tell me about this requirement? How did this requirement affect the program?

KP: I really can’t speak to any requirement generated by Ft. Benning, you’ll have to go to them for more information. The 1,200 m shown in my NDIA slides is just a “rule of thumb” for medium caliber energy measurement, and is not related to an operational requirement.


TFB: The 6.5mm CT so far appears to be slated for an LMG and a carbine. This seems to indicate that CTSAS is designing for a one-round Army, replacing all 5.56mm and 7.62mm weapons with the new 6.5mm CT weapons. Is this the case? Why was this decision made, if so?

KP: No decision has been made – we are providing the 6.5mm so that soldiers and leadership can evaluate it against the 5.56mm and the 7.62mm. It will be fired from the CT MMG (not LMG) and the carbine.


TFB: The 6.5mm CT according to LSAT’s slides weighs 15.4 grams per shot, compared to the 12 grams per shot of brass-cased 5.56mm. In a couple of articles I wrote, I examined the weight penalty of using a round this heavy as a replacement for both 5.56mm and 7.62mm. Does the CTSAS program consider this weight penalty acceptable, or not? If so, is the idea to reduce the number of rounds carried by the infantryman in exchange for greater effectiveness of the individual projectiles, or is the 15.4 grams just the current state of things, the weight of ammunition expected to decrease with development?

KP: Since the 6.5mm is a heavier projectile than the 5.56mm, and it requires more propellant to achieve the necessary velocity, it will probably always be heavier than the 5.56mm round. This is an option that is being offered for a round that provides considerably more range and performance than even the 7.62mm, so that is actually a better comparison. The trade-off between weight and performance is totally up to the user community, and not the technology developer.


TFB: Textron recently showed off their mockup for a 6.5mm CT carbine at AUSA. According to their representatives, the 6.5mm CT round they are using (I am assuming this is the same round as the CTSAS cartridge?) produces 3,000 ft/s muzzle velocity from the carbine’s barrel with a 123gr bullet, for almost 3,400 Joules. This is much closer to 7.62mm NATO performance than 5.56mm. How does this change in performance affect the rifle, and is this performance something demanded by Fort Benning requirements, something done deliberately by the CTSAS team, or a byproduct of the chamber volume of the 6.5mm round (which shares external dimensions with 7.62mm CT, correct?)?

KP: This improvement in performance is being done deliberately by the CTSAS/Textron team (we are all on the same team). The rifle is being developed concurrently with the ammunition, and so there are no expectations that it will degrade the performance of the weapon. The 6.5mm round performance actually exceeds the performance of the 7.62mm round, at a lower weight and impulse. The 6.5mm and 7.62mm CT projectiles are being packaged in the same cartridge case only for convenience at this time. It allows us to use either round in the weapons with only minimal changes to the weapons (mainly the barrel). The 6.5mm cartridge could be made slightly smaller in the future.


The Textron 6.5mm CT Carbine. Taken from a slide in the 2016 NDIA Armaments Conference CTSAS presentation given by Kori Phillips.


TFB:Is there a worry that the vastly increased performance of the new round will adversely affect shooter recovery time and weapon handling in fully automatic mode?

KP: No, shooter controllability has been accounted for in the weapon and ammunition design.


TFB: How was the 6.5mm caliber chosen as the third CT round? What requirements were involved that led to the selection of that configuration? What thresholds needed to be met, if any, for the 1,200m range requirement (e.g., “retained energy of 300 ft-lbs at 1,200m”)?

KP: The NDIA briefing that I gave at the Armaments System Forum in April 2016 describes the caliber optimization study in some detail. The basic concept was to provide required velocity at a specified range (not shown) and threshold impact energy at 1,200 meters, at the lowest possible impulse and weight.


TFB: The .264 USA is often mentioned alongside the 6.5mm CT as a sort of “conventional counterpart”. The .264 USA is however considerably less powerful (~2,700 J vs. ~3,400 J). The AMU obviously being a separate entity to Picatinny, has there been any cross-pollination there?

KP: The AMU did provide us feedback on the actual projectile, which is very similar for both systems. I am not aware of the characteristics of their cartridge, but they are constrained somewhat by the use of a legacy cartridge and weapon design, and the goals of their program are slightly different.


TFB: The weight savings of a 5.56mm CT round is considerable versus the standard brass-cased variety. Does the CTSAS program see a future for 5.56mm CT or not, and in either case why?

KP: It depends whether the user community prioritizes weight or performance.


Original caption: “Spc. Luke Anderson fires the LSAT LMG at a 100-meter target at Fort Benning, Ga.” Image credit: Eric Kowal, RDECOM. Public domain.


TFB: The current Textron 6.5mm CT carbine uses magazines of 20 rounds capacity, 33% less than that used by the current M4 Carbine. Is this deemed an acceptable decrease, and if so why? If not, are higher capacity magazines being sought/developed?

KP: We could not find any doctrinal guidance on how many rounds should be in a magazine for a combat rifle, and when we looked at 7.62mm rifles for comparison (like M14 and MK17), they have 20 round magazines. The only impact of having a higher capacity magazine would be the overall size (and weight) of the magazine, since these rounds are bigger than 5.56mm rounds.


TFB: Right now, the weight of equipment carried by the infantryman is very high, which presumably means there is a crunch on how much weight can be added or needs to be saved for various pieces of equipment. The LSAT/CTSAS team has already innovated in this area, but the Textron 6.5mm CT Carbine is still heavier (with heavier ammunition) than the existing M4/M4A1. Moving forward, how does CTSAS plan to reduce the weight carried by the soldier, and will we see a further weight decrease thanks to the technology being developed through this program?

KP: The 6.5mm system may increase weight slightly over the M4 if it is carried with the same number of rounds of ammunition, but if the ammunition proves to be more capable, some decisions could be made to change the standard combat load from 210 rounds (current) to something less (notionally enough to balance the weight between the two systems). The CTSAS/Textron team is not in a position to make these kinds of decisions, but we wanted to offer the decision makers an option that would provide a capability that exceeds what they currently have at the smallest possible weight penalty. There is always opportunity for additional weight savings or tradeoffs, depending on the priorities of the users.


TFB: I mean, that 6.5mm CT round is a monster! It’s producing like double the energy of an M4. Is that something you were able to get away with because you’re getting better efficiency out of the propellant, and also because you have the soft-recoil LMG?

KP: The thing we were using for comparison was weapon impulse, so we didn’t consider the weapon platform. We wanted it below a certain threshold, but because the 6.5 was a fairly small bullet, we could jack up the velocity and still not go above our impulse threshold. We ended up using the 123gr Sierra MatchKing for testing.


TFB: The 1,200 meter distance mentioned in your presentation didn’t end up being what I thought it was. How did you come to that?

KP: That is just a standard test distance, there’s no operational requirement associated with it. When they test 7.62mm guns, they test them out to 1,200 meters. We chose that number because that was a good place to compare what our bullet would do to what 7.62mm would do. It’s more of a medium machine gun range, and we wanted to push the MMG out beyond what an LMG would do.


TFB: That sort of suggests that the 6.5mm CT is intended to be kind of a maximum configuration round.

KP: In addition to the carbine, the 6.5mm ammunition will be used for the CT Medium Machine Gun , which could replace the M240B and M240L. We wanted to make sure it could do as well as that weapon system or better. The CT Medium Machine gun with 800 rounds of CT ammunition (either 6.5mm or 7.62mm) weighs the same as the current M249 with 800 rounds of brass cased 5.56mm ammunition, and provides far more capability. And when it’s done, the carbine will weigh around 8 pounds, which is more than an M4, but keep in mind the performance exceeds a 7.62mm rifle, which tend to weigh significantly more.

Nathaniel F

Nathaniel is a history enthusiast and firearms hobbyist whose primary interest lies in military small arms technological developments beginning with the smokeless powder era. In addition to contributing to The Firearm Blog, he runs 196,800 Revolutions Per Minute, a blog devoted to modern small arms design and theory. He is also the author of the original web serial Heartblood, which is being updated and edited regularly. He can be reached via email at


  • Renato H M de Oliveira

    This is one of the most interesting series of late, thanks for your work!
    Is it just me, or Big Army still thinks on 2 calibers? 5.56CT for general purposes and 6.5CT for MMG and maybe, just maybe, a secondary carbine?

    • Jason Culligan

      Makes sense though in all fairness. The 6.5CT looks like it’s optimised for replacing the standard 7.62 NATO given it’s specs which would make a 6.5CT carbine a battle rifle. Equipping frontline troops with battle rifles has proven to be a costly failure in the past.

      The only way I can see a full 6.5CT army working is if exosuits or a new lightweight armour technology appear for frontline use alongside 6.5CT carbine. Otherwise the weight penalty would seriously restrict a squad’s firepower compare to a 5.56CT carbine or current M4’s.

      • Renato H M de Oliveira

        There are quite a few debates on the validity of carrying a lot of inefficient rounds vs many rounds of a more effective loading.
        Which is the optimal compromise? Maybe something weighing the same as the current M855A1, but firing a bigger/heavier pill at same MV? Same pill at a higher MV? Or something in between?

        • George

          There was a lot of talk on the previous LSAT / CT articles on optimum.

          I and others advocated exploring a heavier longer 5.56 CT and 6CT with weight limit at or slightly under 5.56×45. The brass round is probably light enough now – 200 plus round rifle loads (seen many hundreds), and better range and ballistic coefficient in same weights is not a bad thing.

          I think reloaders would already be doing that if the specific powder modification for the compressed powder loads were known and available…

          • Renato H M de Oliveira

            Agreed. An M855A1 with decent form factor (even in 223) would be a nice starting point for a good CT.
            The worst limiting factor for current 5.56×45 weps is COAL. You can negotiate with everything else by fitting new barrels and sights, but COAL is a no-go.
            If you duplicate M855A1’s design and features in a longer projectile you might possibly be able to get some decent ballistics out of it. Other options are 7N6 and Balle D as starting points.
            If you’re going to use 2 or more calibers, then long range isn’t a must, and you can limit yourself to 500m or below. That allows a lighter cartridge with same or slightly improved ballistics, or equal weight and vastly improved ballistics.

          • Johannes von’ Strauch

            A 5.56CT with improved shape greatly exeeds 500m, it can have a supersonic range of 1200meter. (And a human is a sack filled with vital organs and bones, at any range a supersonic projectile will really mess things up)

          • Renato H M de Oliveira

            With decent BC and mass, all that while lead free? Will it be easy to stabilize in military conditions?

          • Johannes von’ Strauch

            Yes, actually not that hard to do. And additionally with one specific Patent it beats 6.5mm in trajectory, supersonic range, wind drift, time of flight, and even energy retention at range.

          • Renato H M de Oliveira

            Very interesting, where can I find more info?

    • roguetechie

      It’s not just you that sees it, and at least IMHO it’s a good thing that they’re still looking at a 2 caliber system.

      The reason I say this is that the battlefield is becoming a more and more complex place where trying to pack enough of the right kinds of performance for a good cross section of the threats we might face is becoming very hard to do with even a 2 round solution!

      Looking at the only true peer competitor the United States has currently (China will no doubt get there but isn’t quite there yet right now. Mainly because they are still in the process of changing their force into one more expeditionary in nature.) is the Russian federation.

      The Russians, who are very smart and capable potential foes, have essentially given up on even trying to limit their own caliber suite to just two cartridges which even at the current juncture is an extremely expensive undertaking to make two cartridges truly capable of filling all the roles that a modern military needs to fill.

      They for the most manage to fill the majority of roles with 7.62x54r and their THREE x39 cartridges. (5.45, 7.62, & 9 millimeter)

      If you throw in PDW’s and pistols and or the heavier stuff that they can and do use as the situation calls for you also find the Russians branching out or doing things completely different than we do in the west. Good examples being both the KORD HMG and another even lighter 12.7×108 man portable and usable machine gun that frankly there is no western analog of.

      Long story short, I personally believe it would be pure stupidity to attempt a single cartridge one size fits all solution when our closest competitor seems to have a cartridge and gun design for every occasion.

      • Renato H M de Oliveira

        Agreed 100%.
        The Russians not only have a gun and caliber for each scenario, they also have forces/agencies for each situation – FSB, KGB, Spetsnaz, etc etc, each one of them with different weapons. That simplifies matters.
        What also helps them is that their ROEs are far more permissive, perhaps even too permissive. Match such ROEs with different support vehicles and you have very effective armed forces.
        Western nations can undoubtedly do better, but “our” mindset and political crapness ties our hands in the back.

        • roguetechie

          Yes indeed,

          It definitely leaves us hunting around the perimeter of a problem for solutions while the Russians just do a grad battalion fire mission with thermobarics and not only is the problem solved, but there’s no one left to complain to the UN

    • Hopefully we’ll see 6.5 PCT adopted in the SAW role, as a sort of futuristic PKM.

      • J

        6.5CT can be greatly outperformed at lower weight, flatter trajectory, supersonic range, more mag/pouch capacity. And… FAR less recoil.

        • Could you expand on what would match / outperform the 7.62×54 PKM with less weight and recoil then the 6.5?

          • ostiariusalpha

            There’s always “that guy” in a forum or comments section that knows a super-secret, revolutionary new firearm or ammunition design, but they never get around to showing it, or even really describing it adequately. Maybe 99.9% of them are deluded nutjobs, but you always kind of hope that at least one of them isn’t blowing smoke. Charlie Kelsey was a nut, but he was also a genius that people really did try to steal his designs from him. So who knows?

          • I want to believe.

            It’s just that matching the range, and especially barrier penetration, of the 7.62×54 (launching a 150gr @ 2800 or 180gr @ 2600) seems like a tall order for a caliber “substantially lighter” then the 6.5 123gr.

          • So may have found a slightly lighter option that could outperform the 6.5.

            Cutting Edge Bullets makes a 6mm solid copper 100gr 6mm bullet with a .560 BC. Per Hornady Ballistics app, if launched at 3,000 fps, thats doing 405 ft/lbs at 1200 yards, about 100ft/lbs over the 6.5 PCT claims.

            However, that’s with a ludicrously nice, swiss lathe bullet. A EPR projectile would be of similar weight, but it’s little exposed neck area where the two bullets join would likely increase the drag. And saving 20gr of weight per cartridge, even with 1,000 rounds, is only saving 2.85lbs of weight. And 6.5 likely does better out of shorter barrels, and would have a longer barrel life as well.

          • ostiariusalpha

            Right, I considered a 6mm also, but it has the drawbacks you pointed out and less energy, which is important for a MMG/DMR round. The little radial channel where the jacket and penetrator join together doesn’t have much, if any, discernible effect on BC, according to Nathaniel F.

          • ostiariusalpha

            You know, I wonder if putting that 6mm bullet in a sabot might not do the trick. I doubt plastic sabots would do well in a machine gun barrel (maybe?), though perhaps a bimetal or copper-washed sabot might do the trick. Flechette sabots have had ballistic precision difficulties that have held them back, but “cup” sabots used with standard bullets don’t seem share that problem. So a .308 CT cartridge with a .560 BC 6mm projectile imbedded in a .30 cal sabot might just be the cat’s meow, you get increased range and lowered heat flux. If the plastic sabots turn out gtg in a machine gun then you’re really getting a big bump in capability.

          • I think you are onto something (and I wish we were running a ballistics lab to test this.)

            So a 110gr Lehigh .308 launches at 3400fps. Assuming 100gr bullet + 10gr sabot at the same speed, you have a bit less recoil then the 7.62 NATO, but an absolutely insane ballistic performance:

            6mm PCT Sabot
            Muzzle: 3400fps/ 2567 ft/lbs
            -100 yards 3213fps – 2292 ft/lbs
            -300 yards 2864fps – 1821 ft/lbs
            -500 yards 2540fps – 1433 ft/lbs
            -800 yards 2096fps – 976ft/lbs
            -1000 yard 1827fps – 741ft/lbs
            -1200 yard 1584fps – 557 ft/lbs
            -1500 yard 1279fps – 363 ft/lbs

            When you compare it to M80 Ball 147gr @ 2750 w/ a .393 BC, it very impressive, especially when it comes to drop.

            6mm PCT Sabot vs 7.62 M80 Ball drop
            300 yard: 7.5″ vs 14.5″
            500 yard: 32.1″ vs 61″
            800 yard: 111.5″ vs 226.9″
            1000 yard: 207″ vs 439″
            1200 yard: 336″ vs 772″
            1500 yard: 646″ vs 1560″

            So, bring on the Sabots!

          • Johannes von’ Strauch

            With 3400fps and a 10grain sabot you waist 348Joule. Much lighter and highly precise sabots are getting developed.
            And as said before full copper projectiles wont perform as well as one with a hard steel head against barriers, armor, and does not fragment/segment in flesh.

          • Whose working on light and precise sabots? I’d like to look more into it.

            The copper solid was not to represent the ideal projectile, it’s just the heaviest lead free 6mm VLD that I could find, and is of comparable weight/ density to the copper / steel EPR.

          • Johannes von’ Strauch

            Btw, always consider that BC’s arent constant at all. With a given G7 BC you can drastically overcalculate things if theyr not meant for the range you calculate at.

            A G7BC for 800 or 1000m or yard will completly overperform at 1200m (1312,336y). So you need the 1200m G7BC and then calculate energy etc (+ know that in the range between your energy is more than calculated).

          • Johannes von’ Strauch

            There are a lot of problems with sabots, but really good configurations work extremly well.
            Dont worry, those things are in development.

            But keep in mind that a full copper projectile wont perform as well as one with a hard steel head against barriers, armor, and does not fragment/segment in flesh.

          • Johannes von’ Strauch

            My entire life is dedicated to nothing but ballistic. I do nothing else since years. It took an insane amount of time, but damn, boundarys will change.

          • Johannes von’ Strauch

            *and yes i know what you mean, people often come up with theyr new Übermensch round, they present cherry picking… but which ends up a bs 6.8spc copy with stupid weight, low velocity, insanly bad form factor, high recoil, bad trajectory.
            Ive read most of theyr forums, pdf’s, presentations, etc. Few (almost none) of them even properly uses existing boundaries, which means all of those rounds greatly underperforms to whats commonly possible, so actually pushing boundaries with new innovations/patents is already fully out of any reach in those cases.

            I know just a single person, who barely slipped by one key innovation, but didnt noticed it.

  • Blake

    So basically this is like the 6.5 Grendel 123gr SMK target load, but ~400fps faster?

    Daddy Likes 🙂

    • Giolli Joker

      Basically 6.5 Creedmoor.

      • Paul Joly

        “the 6.5mm CT […] produces 3,000 ft/s muzzle velocity from the carbine’s barrel with a 123gr bullet”
        What I find on internet is more 2700-2800fps muzzle velocity for 6.5cm with a 123gr bullet from 16″ barrel. They must have based their bullet on the recoil impulse of the 7.62nato m80. Therefore it isn’t suited for an infantry carbine IMO.

        • glenn cheney

          Keep in mind, they are using proprietary propellants not normally available to civilian consumers and their picking up the additional velocity is likely the explanation, all other aspects being held constant. They are “recipes.”
          6.5 Handloaders currently are maxing out pressures trying to duplicate the Hornady performances, it’s the powder I’m told, bwdik.

          • Paul Joly

            You didn’t get it ; I meant that the recoil is too violent for someone who needs to hit quickly moving target at 50-200m with less than 500rds fired in his life with the weapon system he’s using and no prior experience of shooting another similar weapon system.

          • glenn cheney

            We are in deeper Doo than I thought, if recoil from any 6.5, Grendel or Creedmore is an issue.
            I’ve burned 500 rounds at MacDill in a single session in 30-06, yes, lol, we wusses got tenderized. Where is Uncle Sam finding these greenies?

          • georgesteele

            So you ended up with a flinch, which adversely affected combat accuracy and efficiency, which, when the statistics were compiled, convinced DoD to increase ammunition capacity, which added weight so that they had to go to a lighter, smaller caliber, so that now we have a camel.

          • CT is using propellant similar to CFE223, I believe. It’s a variant of St. Mark’s propellants like SMP-842.

          • glenn cheney

            T.Y., Appreciate your tolerance for speaking freely, Sir. !

          • glenn cheney

            St.Marks, will tweet to customer needs, so I infer similar to mean it likely more than their ball powder.
            America depends upon them, as last I checked, of five mfgr propellant supplies to the US civilian consumer for reloading, they are the only domestic.
            I always sweateded the previous admin. and their influence over a primarily military contractual supplier.
            A General Dynamics sub., we depend upon them more than we realize.

        • noob

          They should have branded the “carbine” as a “compact dmr”. That would have answered any questions about the 20rd capacity, the weight, the reduced number of rounds carried etc.

          • Paul Joly

            Don’t be limited by the “standard” type of configuration. You can have a firearm with a 9″ barrel shooting projectile at 3000fps or a 1″ barrel shooting submoa.

          • noob

            a sub moa snubby? now that would be an interesting bull barrel firearm

    • yodamiles

      Didn’t you made a comment a while back (like 2 years ago) about the merit of low drag .20 bullet? What do you think about 55gr .20 bullet load (Or even as extreme as .172″ 37gr Berger VLD) as the replacement for 5.56 in CTSAS configuration?

      • Blake

        Wow, good memory.

        A bullet like the 62 grain Unmussig (biggest .20 cal bullet, far right example in the pic) configured like the m855a1 EPR would be a significant improvement on m855a1, & e.g. still be barely supersonic at the required 1200yd testing range.

        According to JBM, if CT technology could launch such a bullet at ~3800fps, you’re looking at a round with a >450yd MPBR! (I don’t have the specs for the 62gr so I used the data from the 55gr Berger). Lethal (>800ft-lbs) energy is retained out to 450-500yds, unlike m855a1 which drops under 800ft-lbs @220yds. This would be pretty impressive in a CT configuration for smaller weapons like PDWs (or even handguns).

        However, doing a JBM run for the 6.5mm 123gr SMK/CT load @3100fps shows us that it has a ~400yd MPBR & drops under 800ft-lbs @800yds, & stays supersonic beyond the 1200yd required testing distance. Very impressive stuff.

        • yodamiles

          These lighter bullets might allow CTSAS to achieve 50% weight reduction compare to 5.56. Kinda painful to see people skipping over these bullets.

        • That’s very interesting. However given the lower weight density of hardened steel and copper found in the EPR, I’m not sure if a 62gr .20 cal would be possible without making the bullet too long?

          • Blake

            That’s the beauty of this project & CT in particular: it’s a greenfield “clean sheet of paper” designed from the ground up around an optimal cartridge. So if a 62gr .20 cal EPR is determined to be the optimal bullet for an application (e.g. PDW or handgun as I mentioned earlier), then you design the weapon around the cartridge from scratch). A pistol design like the GSh-18 could easily handle the higher case pressure that makes CT sing (e.g. 7n31 is a 63 gr bullet @2kfps; the .20 cal bullet at that weight & speed has a ~250yd MPBR, from a pistol!)


          • The clean sheet aspect of the PCT project is really the most exciting aspect of it, and I hope it gets taken maximum advantage of, rather then just sticking a M855A1 projectile into a PCT case and calling it a day.

            The .20 sounds very interesting, but I foresee a few drawbacks. First, and really the biggest, is that the narrower the bore diameter, the longer the barrel required to drive a projectile of the same weight to the same velocity.

            This was one of the reasons why the 5.7×28 was able to work in a handgun, but HK was unable to get adequate performance in the 4.6 UCP pistol. In fact, full powered loads (Elite, R&R Weapons, and handloads) for the 5.7×28 4.85″ barrel are able to nearly match the velocities of the 4.6×30 out of the 7″ MP7, despite the 4.6×30 having a 7kspi higher operating pressure. The Five Seven can launch a 40gr @ 1950fps, while the MP7 launches a 40gr at 2,000fps.

            So my concern is that a .20 would face a similar handicap in terms of velocity relative to barrel length. It would likely take an even bigger hit then 5.56 when fired out of SBR length barrels, and would likely be mostly flash out of a Pistol length barrel.

            Check out Bullberry’s .204 Ruger velocity test, there’s a 150fps loss just from going from 16″ to 15,” and once he hit 14″ blast became so great that the Chrono ceased to function.

          • noob

            slightly off topic, but I always wondered why FN never made an auto-sear for their Fiveseven handgun. Had they done that, and added a stock and some kind of ugly muzzle shroud with an optics rail, then the HK MP7 would have been dead in the water and PDW standardization would have been a slam dunk.

            HK would have said “but but gas operated!” but FN could have said “yeah but look at our attractive price tag!”

          • That’s something I’ve thought as well. If they made a provision for a 2-3 round burst mode for the FsN, any concerns about “stopping power” would be over. And given the low recoil of the cartridge, it would likely be quite controllable for 7-15 yards, similar to the Colt SCAMP.

            But I agree, if they really wanted PDW standardization to become a thing, they should design an goldilocks weapon between the FsN and the P90, something like a B&T MP9 that takes FsN 20 and 30rd mags, and weighs closer to 2.5-3lbs with a 12-13″ length folded. The MP7 is 16″ collapsed and 4.2lbs, so they could easily drink their milkshake.

            Alas, FN seems to be focussed on selling generic AR15’s rather then upgrading their advanced firearms (FsN, P90, SCAR, F2000.)

          • Blake

            That is indeed a very interesting observation, & one I hadn’t considered.

            I think that this can be overcome, however, thanks to a few things:

            – we’re not talking about a compact handgun here but a round that could be used both in a full-sized military handgun as well as a PDW, so 5″ minimum bbl length wouldn’t be unreasonable if the rest of the weapon is a clean-sheet greenfield designed specifically for PCT.

            – the powder charge used in CT is both compressed and a “leverrevolution”-style “longer-pressure-peak” powder; this could be further optimized for short barrels (since unlike 5.56 you’re only using it in handguns & PDWs).

            – since we need a high (1/7) twist rate to stabilize this heavy-for-caliber bullet, perhaps polygonal rifling (or other creative methods) will provide less resistance on the bullet.

            – to paraphrase the Bulberry article: “20 VarTarg maintain better overall performance in short barrels due to the smaller case and powder charge.” So we want just enough case volume to get our 62gr .20 EPR up to 2kfps from a 5″ pistol bbl.

            – while we’re at designing greenfield weapons, let’s build a low-maintenance integral suppressor into the PDW to deal with that muzzle blast :-).

          • I’d be very excited if PCT could somehow get sabots to work consistently and accurately, as that would allow for much higher velocities out of shorter barrels.

            A 9×23 Winchester powered round would easily be able to launch a saboted 62gr @ 2,000fps from a 5″, likely higher (the .357 Sig 60gr RBCD was alleged to be 2400fps.)

            Sabots would also allow firing of solid hardened steel and tungsten projectiles, similar to the 6.5 CBJ.

          • Renato H M de Oliveira

            Long pills don’t mean only big COAL. There’s the 5.5 (or so) calibers length limitation on pill’s stability through rifling, before it becomes impossible to properly stabilize except for fins.

          • politicallyincorrectshooter

            Look at the Voss eds from Cetme. He managed some interesting results, and there was another article here…

          • Renato H M de Oliveira

            Ah, the Voss.
            Its materials include aluminum; very lightweight but lacking in penetration.
            But I do agree that the form factor is interesting.

    • It is extremely similar ballistically to the .260 Remington.

    • n0truscotsman

      If it is the same weight as 5.56 and doesn’t take up any more space, then yeah. Itll be an interesting ‘what if’.

  • Aono

    The 6.5mm 123SMK has a form factor of 0.970 (G7 .260). This is not shabby, but there is considerable room for improvement as bullets like the Berger 130s (.927) and Norma 130s (.905!) illustrate, as well as the 7N6 (.931) and 7n10 (.939). I would be surprised if the actual 125gr 6.5mm CT projectile did not enjoy at least the conventionally accepted “VLD” threshold form factor of 0.950 (lower is better). But, let’s stick with the 0.970 form factor, 3000fps muzzle velocity, and notional minimum impact energy of 300ft/lbs.

    As indicated by the slides, a 125gr 0.970 bullet leaving the muzzle at 3000fps will exceed 300ft/lbs at 1200m. If we substitute a 55gr bullet with the same ~0.970 form factor and 3000fps muzzle velocity, it just happens to achieve 300ft/lbs at 600m, or exactly half the effective range. That seems to me to be a pretty obvious high/low mix replacement to match or outperform the 5.56/7.62 of today in both effective range and loadout weight. And these are pretty conservative numbers given the likelihood that the achievable form factors are likely closer to 0.950 if not lower.

    Where it would really get interesting to me would be to also optimize a CT round around the requirement of the rough dimensions of a 9mm double stack magazine, basically adding a notional COAL requirement to the weight and impulse factors. This would seem to me to already be a very, very close fit to the existing 55gr 5.56CT round. Rather than attempting to combine 5.56 and .308 into one new CT round, you would be combining 5.56 and 9mm into one new CT round.

    Kori said that “the trade-off between weight and performance is totally up to the user community,” and this would very much be in the spirit of preserving that choice for the actual end-user, who always tends toward smaller and lighter, over and over again. If the siren song of transformative standardization has seemed to call for combining two cartridges into one, let it instead combine three cartridges into two. 9mm is the obvious anachronism that should be sacrificed to the gods of standardization, not 5.56 or .308. We do need a 1200m overmatch GPMG and DMR cartridge for fires. We also need a cartridge lighter than 5.56 NATO for maneuvers. But physics can’t do both in the same cartridge and we shouldn’t pretend that it can. And the one thing that NO ONE needs is 9mm. So let’s see some forward-feed CT PDWs designed around a magwell that fits a human hand. Let’s see a subsonic option in the same dimensions. Then let’s see what the end-user actually starts to take with them when given the choice.

    • Renato H M de Oliveira

      Good analysis.
      But some of your points assume lead cores, while Army is going to lead-free. The best lead free military rounds I know of are Balle D and 7N6M.

      • Aono

        True, but then there are civilian lead free projectiles that achieve head-snapping sub .700 form factors, like the Warner Flat Lines. As you and Roguetechie indicate the limiting factor for a notional magazine COAL constraint is projectile length. But 5.7×28 at 1.594″ is already longer than 5.56CT at 1.556″, and 5.56CT is already between 9mm and .40S&W in diameter. So if not fully double stacked, then at least staggered. If the CT nose sleeve could take on a rounder profile without hurting the forward feed (which might also benefit seating concentricity a la toroidal bolt lugs), and the projectile shape and velocity optimized, I would imagine that a 300ft/lb@600m cartridge, in handgun magwell length and optimized for a carbine length barrel, would be doable. If short barrel flash then is a problem for either the low volume rear echelon users, or the HSLD CQB LIIIA users, well, that’s what cans are for and the 600m requirement is gonna matter less anyway. And they’re all still carrying the same thing that the belt fed guys are carrying tons of.

        TLDR: I’m advocating the idea of stuffing M855A1 into a handgun magazine by way of better form factors and CT (to include that compacted powder column whizbangery). The M855A1 form factor remains total crap, which I’m sure has a lot to do with the constraints of the 5.56NATO chamber, so there is a lot of room to improve there. 5.56CT is already at least the right COAL if you compare it to 5.7×28. This idea seems to me to be within reach, even if at first blush a cartridge you can belt feed AND put in your holster sounds a bit outlandish.

        • George

          If you are going to do that, don’t fixate on OTS 5.56CT. Look at .300 BLK and consider shorter cartridges optimized for shorter barrels.

          • Aono

            You’re not wrong, but I think an overriding concern with LSAT and CT and so on is that we are at risk of making some poor trade-offs in the name of commonality and standardization, i.e. ditching both 5.56 and 7.62 in favor of 6.5CT. I think most people understand why the weight tradeoff there represents a real downside, and one which history has replayed over and over. And I say that as an irrational fan of all things 6.5.

            But one of the premises for arguing for commonality is that it would ostensibly give, say, NATO allies, a budgetary rationale to change calibers at all. And commonality does have real upsides. So if one of the choices must go under the bus, then make it 9mm, not 5.56. Better to combine the roles that 9mm and 5.56 play than the roles that 5.56 and 7.62 play. You can always optimize different loads for different barrel lengths within the same cartridge, like Mk319 vs M118LR or Mk262 vs Brown Tip.

            That said, there’ll definitely still be a need for a subsonic optimized cartridge in an integrally suppressed firearm. But I would argue that will remain a niche need that should be addressed by fielding multi-caliber designs, rather than a general purpose cartridge that might take the place of something with lighter weight, greater effective range, able to defeat body armor, and limit over-penetration. Not to mention work in the belt fed. (there’s that commonality again)

        • Renato H M de Oliveira

          You can modify CT as you wish. As long as the pill stays within the case, its shape or length matter not regarding feeding.
          Kori says so during this very part of the interview. What she also makes clear is that it isn’t up to her to make ballistics and other considerations – the customer (in this case US Army) says what they want, and she does the trick.
          But regarding handgun ballistics… There was a debate some time ago in Tony Williams’ forum exactly abou CT handguns. The consensus (well, sort of) is that a handgun is basically useless past 25 m (most possibly even less), except in the hands of Jerry Miculek and a few other accomplished shooters.
          If you need more range, then you need a rifle/carbine sized weapon. SMG might be an option, but there are SBRs out there that can match or even improve on bulk & weight, with some AR builds being actually lighter and smaller than the HK MP5, which still is the “gold standard” when you talk about SMG.
          If you work within this distance, then a 9x19mm is actually a pretty good caliber, offering a nice blend of size, weight, energy, momentum and report. Not to mention a myriad of weapons and loadings for it, made worldwide.
          If you throw in body armour defeat, then 5.7×28 fits the bill. It sucks on everything else, except for size, weight and recoil. 5.8×21 will probably be a bit better here and a little worse there, but largely equivalent.

        • gunsandrockets

          Why not just use a revolver for your new common handgun/rifle round?

          Of course any handgun with a normal handgun barrel length is going to have a ridiculous muzzle flash and report with a cartridge like that.

    • roguetechie

      As Renato sort of points out lead free 7n6 and balle D are both very long bullets which are required to achieve both good ff and have any hope of something resembling a good sectional density.

      That’s going to be very tricky to achieve in a double stack magazine well that fits the human hand.

      Some other bullet designs to look at when considering this would be the bullets from 7.92×40 Cetme Voss as well as the 5.56 FABRL bullet designs.

      Though one really neat thing to consider is just how much better of a 5.56 can be made while still keeping weight ridiculously low with a polymer cased telescoped case.

      A design I’ve seen some basic calculations done for indicates that essentially a “saboted” 5.56 (the sabot being basically “free” because CT requires a nose cap!) using M855a1 style projectile construction and the AR-2 FABRL shaping etc nets you a 55 grain projectile developing nearly M16a1 muzzle velocities from a 10.5 inch barrel while weighing in at around the same weight as 5.7×28 rounds.

      That’s worth pursuing regardless of whether it fits in a double stack 9mm magazine well or not!

  • iksnilol

    How light could they get it if they tried to match 5.7mm??

    • ARCNA442

      I wonder if CT could make the PDW concept more viable by allowing a round the same length and weight as 5.7 but with effectiveness closer to 5.56.

      • The problem would be barrel length and blast.

        An MP7 style weapon firing a 5.56 PCT might be able to fit within the pistol grip mag, but then you’d have a 7″ barrel 5.56- which what we’ve seen from 5.56 ‘pistols’ makes for intolerable muzzle blast and flash.

        • Aono

          That’s just a function of burn rate. Think the spectrum between pistol and magnum rifle powder.

        • ARCNA442

          That’s a good point. But if you’re optimizing it for a short barrel and close ranges you could probably use a bit less powder without loosing too much effectiveness. Plus some sort of micro suppressor could likely be devised if the blast was still too bad.

          • noob

            Hmm if it doesn’t change the sound signature but contains the blast can that avoid the $200 tax stamp?

        • XT6Wagon

          what if you did it P90 style with a PS90 length barrel. Its not a pistol, but going to be superior to any of the current SMGs outside of distances you could throw the gun at them and hit them. You would still need to design the round to a 10″ barrel or suffer for it.

          • I guess the question is whether we’re talking about dedicated PDW weapon / cartridge system, or simply adopting the 5.56 PCT into a PDW sized weapon?

            One cool thing about the 5.56 PCT being so short is that a rifle could be designed with the magazine inserted into the pistol grip, which allows for a shorter weapon without going bullup. For example, a 16″ SUB 2000 is only 29.5″ long, whereas a CZ Evo carbine with its forward magazine is 34.5″ So you get a comfortable length decrease in between bullpup and conventional layout.

            And, if you chop down the barrel, you get an easy, “good enough” micro carbine in 5.56 PCT, without designing a new firearm or caliber.

            So a 5.56 PCT SBR could be quite a bit smaller then a 5.56 NATO SBR, likely comparable in size to a MP7 or P90.

            But if the goal is designing a dedicated PDW/ Caliber combo, the round would have to be able to work in a 5″ barrel so that it could be used in both handguns as well as a much more compact, “holsterable PDW” such as the B&T MP9. A 5.56 power round would be “too much of a good thing” for this role.

          • Aono

            We are thinking alike in terms of stuffing a 556CT into a pistol grip magazine PDW, but I think the short barrel (as in pistol length) concerns are addressable.

            First, with the “300CT” subsonic barrel swap option. Change the cartridge sleeve cap shapes to make them mutually impossible to chamber. The subsonic niche is a niche, but it’s also not going away, so might as well embrace it in this way.

            Second, with a color coded short barrel load that still uses the 5.56CT cartridge and chamber, but with a short barrel optimized powder and much heavier bullet somewhere in the 90gr+ range. Design the associated guns around being able to function (reliably, if suboptimally) with both via adjustable gas, etc.

            I said a lot of this in my comment thread below but the parent comment still appears to be in moderation or something.

      • iksnilol

        Probably. I mean, the CT rounds are shorter. So you could have a 5.56 with a slightly reduced charge in a round the same length.

        I mean, have you seen the CT rounds? The 6.5/7.62 in its entirety is as long as the 7.62x51mm case is by itself.

      • J

        Yes and no. As people say, swept volume is a problem, usually… . But with this push trough chamber, the mechanism gets a LOT more size efficient if constructed well. = PDW’s can have a longer barrel

        Even tough i would additionally prefer sabots for short range….

    • Johannes von’ Strauch

      About 8gramm , with better case design 7gramm

      • iksnilol

        but isn’t regular 5.7 like 6 grams?

        • Johannes von’ Strauch

          Oh i tough you mean the normal diameter 5,7mm. Not 5,7x28mm…

          Do you want to know it? I could calculate it for you. What Projectile weight do you want?

          • iksnilol

            I see what you mean, I thought weirdly. What if you used the standard bullet that is already in use?

          • Johannes von’ Strauch

            Give me 5minutes.

          • Johannes von’ Strauch

            *do you mean Pistol or PDW velocity?

          • Johannes von’ Strauch

            42 grain / 2,72155gram – With an 31grain Projectile roughly 6grain/0,388793gram Powder (slightly decreased because better heat isolation). Polymer really makes a diffrence.

            Due to the light weight, slightly decreased recoil, slightly decreased pressure. Velocity could be further increased.

          • Johannes von’ Strauch

            *notes: I changed chamber volume due to diffrent use of powder. And not used a bottleneck cartridge shape. Case wall thickness is enough for heat isolation and case stability.

            I hope you like the weight.

  • yodamiles

    How about extremely low drag 4.8mm or 5mm to replace the 5.56? The 55gr .20 bullet made by Berger have better BC than some 69gr 5.56. You could probably reduce the case diameter slightly if you go with smaller caliber.

    • yodamiles

      Correction: The 55gr .20 bullet made by Berger have better BC than 70gr vld 5.56.

    • Johannes von’ Strauch

      Copy: With 5.56 CT you get 8gramm (with better case 7gramm), with better projectile shape a really high supersonic range. +even less recoil due to less propellant use.

      At 5mm the pressure becomes really high/ or with normal pressure energy gets low.

      = you dont need to use 5mm, an full optimized 5.56CT is already light enough and has good performance, with less recoil.

      • Johannes von’ Strauch

        *Addition: The 0,195 G7BC for a 55grain is great, but still a 0,96821 Form Factor is utterly terrible.

  • Giolli Joker

    If the accuracy i really there it will be a fine DMR round.
    It would be curious though if 6.5 was to replace 5.56… it would look like a revenge of the 7.62 crowd with limited benefit for the soldier.

    • Renato H M de Oliveira

      Some 5.56 nations are going back to 7.62.
      It seems that sometimes the weight penalty is worth the ballistic gains.

      • ostiariusalpha

        Or they think so, at least. It’s great in hill country, but even Daesh and the Taliban fight in urban areas as often as not.

      • glenn cheney

        All I know is, all the busy contractors with orders, are putting out all comblock calibers, I have no intel re 6.5.
        But, no one I know of is shipping many 5.56 orders, but I only get a peek at local newspspers, but we know Colt isn’t.
        The battlefields in Africa, Syria, Iraq, Afghanistan all are at longer ranges. Demand all seems any caliber but 5.56.
        Witness Federal recently, if they aren’t making plenty, something is up.

  • glenn cheney

    A year ago, here, I posted the 6.5 commeth. Some were courteous and iggied.
    Well now, the naysayers are out in drives with the can’t’s. Conversion is a matter of bolts, barrels, and mags.
    The 5.56 is being replaced. I saw the prototype platform a year ago, said then, it looked like a AR and some EU dirivative were left over a 3 day weekend on the shop bench too close together, and what you see here is the aftermath.
    Lmao. 6.5 b.c. optimal in mathematics, need for 600 to 800 yd. plus rifleman capabilities needed, and 7.62×51 fits neither ammo weight carrying capacity for troops on the move, and designated’s can’t be practical in numbers.
    Deal with it, currently, manufacturer’s in U.S. are choking on component overdose, yet SOCOM contracts are very active, to the exclusion of regular mfg’s, as new operations are running at max, in need of additional manufacturing sq. footage, and their production is 7.62×39, 7.62×54, incl. sniper rifles, light and heavy machine guns, supposedly for foreign buyers, however, it is noted, that all calibers are comblock.
    Uncle Vladimir is producing 6.5 Grendel.
    Go figure, double shift production in the face of domestic caliber rif’s, saturated civilian sales and layoffs with BK’s the financial weather forecast.
    Clearly, there are sounds of marching to different drum beats.

    • Aono

      “Conversion is a matter of bolts, barrels, and mags. ”

      You may want to try actually reading these interviews.

      • glenn cheney

        It is evident, a new platform is desired, it is above my and your paygrade, they’ll let us know when they decide to. I don’t care about what happens in between.

        The comment regarding bolts, barrels and mags addresses the current AR 15 platform that may become extinct in military applications, so bolts, barrels, and mags will become moot.

        I have well more .264 LBC high end barrels than I’ll ever use, but they are destined to mate with a mil-spec AR-15 upper receiver, not a newly developed 6.5 platform.

        I’ll leave you guys to pick at the throats, chambering, receiver config’s, it’s meaningless to my interests.

        Point is, the 6.5 is coming. It outperforms the 7.62×51 beyond 700 yards, remains supersonic well beyond 1,000, and meets the need for frontline troops to reach out and touch when they need to.

        I said it’s coming, it is…what’s the beef?

        Delivery platform, as yet decided upon, will determine what components of the AR platform if any matriculate to the new design.

        • Aono

          The beef is that 6.5CM/CT/USA makes a great replacement for 7.62×51, but carries a weight and capacity penalty with it when compared to 5.56×45. These weight and capacity penalties have plagued military small arms for decades when prioritizing fires on paper over maneuvers in reality. You know what outperforms the 6.5 at 1000m? .338 Lapua. But you wouldn’t want to replace 7.62 with that, right? Same logic applies to replacing 5.56 with 6.5.

          There’s also nothing magical about 6.5 except that it is the sweet spot for 1200m effective range. What if your range requirement changes to 600m? Is it worth the weight? Nope. What if it’s 1800m? Now you’re undergunned. Whoops.

          Point is, latching onto the magic 6.5 caliber number for rifles is making all the same mistakes for all of the same reasons that guy make who say “as long as your handgun caliber starts with 4.” Actually that doesn’t matter at all, so long as you understand what the “effective” in effective range means, and have defined requirements for “range.”

          • glenn cheney

            First, you can’t anchor your argument to the immovable rock of 5.56×45. Further, there is no noticible weight difference between a regular 6.5 Grendel cartridge and a 5.56x 45 and, no one in practical balle terms designs platforms to retract to up to 600 yards, when the 1,200 yard barker does just fine. They don’t like up anymore like it’s French vs. English in the 1700’s.
            IMO, you make too much issue with the cartridge weight, what II do make note of, is why and new stripped down basic 6.5 platform must weigh in at 9 pounds plus. I can build a six plus oz. pounder…I’m looking at one right now, and impulse is of no consequence imo, unless they plan on drafting a bunch of pussyhat wearers.
            Keeping it simple stupid has always been validated in the field, those that try to re-create the new unique wheel make me smh.
            No reason to turn a 6.5 platform into a near ten pound brick, if that is the consequence, the better begin looking at either polymers, or, good ol’ AR-15’s….Ordinance has a history of internal disjunct with constant meddling from pentagon brass experience. You’d never have had the 5.56×45 anyway, had it not been for an ass-kicker named Curtis Lemay, then head of SAC, who had the hat to not take no for an answer to the opinion that only the 30 cal. bullets would be acceptable.
            I read enough to see a 9 plus pound platform sans optics save for some flip up sights…not acceptable, trim two pounds from the platform, add two pounds of ammo, problem solved.
            So, let’s discuss how we can trim 2 pounds from Shirley, and add two pounds to Burley.
            I’m not trying to be belligerent, all knowing or other offensive.
            But, imo, there is no need to build a heavier platform than is necessary, unless they see weight as needed for distance, and I’m not convinced. If they want Creedmore performance from a Lapua cartridge hybred, then call it what is is, an AR-10 platform, and 9 pounds is the going rate in past days, now, lighter versions are coming out.
            So, no one weapon is ideal for all applications, same for boats and planes…trade-offs rule. I still say, if the goal is to kill at 600, 800, 1,000, or 1,200 yards, then give the G.I. the tools to do the job, personally, I’d get the CNC machines turning out 6.5 barrels, throated for whatever cartridge design they decide on, and give it standard lighter weighted AR receivers, be it 10’s or 15’s.
            It’s the b.c. of the bullet they know they want, that has been decided, a year ago or more, what sends it is today’s discussion.
            I’d rather handle a 7 pounder that a 9 pounder, but if I’m getting shot at, I could care less about the 32 ounces, and yes, if over run, I might prefer the 32 oz’s to ne in ammo.
            Lets get tgether and work out a 7 pounder that they’ll buy into, as lobbyists and worms sell the need for as many new dedicated components as we can get them to accept.
            Sounds like a plan. What’s our commission?

          • crackedlenses

            His points are valid and present in the interview. You sound like you’re reading your own desires into the data and speculating on what they could do with it. As it stands, the interview makes it sound like the 6.5 mm. round they’ve developed is one part performance testbed and one part 7.62 mm. replacement.

            That’s a far stretch from “The 5.56 is being replaced.”

          • glenn cheney

            We’ll just have to wait and see now won’t we, putting personalities aside.
            The 5.56 is not efficient dealing with towels hanging out at 600, 700 yards, it’s where the conflicts are, not CQB jungles of Nam or Columbia playing get Farc’d.
            They do imo, intend to replace the 5.56. Perhaps not tomorrow, but unless the battlefield changes, they stand by their range needs, otherwise, the designated crews would be adequate.
            They want riflemen to have similar weight and ammo capacity, with double the effective range if needed.
            Why argue the Model T is or isn’t a car, when we’re discussing a new NASCAR 200 mph frame and motor combination?

          • Aono

            TAANSTAFL. Why not give everyone 50 BMG? Why not fight the last war forever?

          • glenn cheney

            Be glad they don’t let me run chit, I’d send everyone home, extract, and seed the place with MOAB’s…glad you mentioned that.

          • XT6Wagon

            Why haven’t we replaced .50bmg by now? Think we can do better 100 years on.

          • crackedlenses

            It’s established and it still works for its intended purpose. I’m sure we could come up better now, but there would be no motivation.

          • ARCNA442

            I think the bigger problem is that soldiers in general are not efficient at dealing with targets at 600 or 700 yards. Those ranges are best left to crew served weapons so why build individual weapons around them?

          • glenn cheney

            They can get qualified. When incoming requires return suppressive firepower, the 5.56 wrist rockets have to lob with no energy.
            It is clear, due to manpower restrictions, they at least want to make the point at 6,7 800. Whizzing tends to hunker one now doesn’t it?

          • crackedlenses

            “It is clear, due to manpower restrictions, they at least want to make
            the point at 6,7 800. Whizzing tends to hunker one now doesn’t it?”

            Haven’t needed this since we abandoned trench warfare.

          • A 6.5 PCT SAW and DMR seems like it would provide a good 80/20 solution to the range issue rather then equipping everyone with a more powerful round.

            Similar to the Russian model of having each BTR team equipped mostly with AK74’s, supplemented by a PKM and Dragunuv.

          • ARCNA442

            In many ways I feel that the Russians have a better understanding of what is needed for modern ground warfare – their squad weapons being a good example.

            A mix of 6.5mm CT GPMG’s & DMR’s combined with a 5mm CT SBR would probably give us a decent long range capability while lower weight/increasing ammo.

          • Not to mention the Russians have an RPG gunner thrown into the mix as well.

            Personally I think 6.5 PCT makes a ton of sense as a LMG and DMR round. But the M4 / 5.56 brass case should remain until we’ve really studied what the future holds, and what type of performance is optimal for the regular soldier before adding another PCT cartridge and weapon into the mix.

            If we were talking near term infantry upgrade (next 5-10 years) I’d like to see the standard 9 man Squad comprised of 6 men with standard brass case M4’s equipped with 1-6x optics and M855A1.

            6.5 PCT LMG, with optic, for use as the SAW. This would provide a weapon/ammo combo a bit heavier then the M249, but with more range and barrier penetration then the PKM.

            Then a 6.5 DMR equipped with a magnified “smart optic” that adjusts the reticle for range, similar to the Steiner ICS. Possibly with the option of a linked electric trigger similar to how the Tracking Point works, increasing the probability of the rifle actually being able to be used to 1200 meters.

            Lastly, a dedicated Grenadier with either a 40x51mm Milkor using airbusting ammo and a fire control computer sight, or a quiver full of Raytheon PIKE missiles, with something like a B&T TP9 in 9×19 as a PDW.

          • crackedlenses

            “The 5.56 is not efficient dealing with towels hanging out at 600, 700 yards”

            That is not it’s purpose, and that is not the purpose of the infantry rifle, at least on the current battlefield.

            “it’s where the conflicts are, not CQB jungles of Nam or Columbia playing get Farc’d.”

            Yes, because all forseeable future conflicts are taking place in mountainous ME countries, just like WWII was going to be a continuation of trench warfare.

            “They do imo, intend to replace the 5.56.”

            They may very well intend to, but it is not explicitly stated and is speculation on our parts.

            “They want riflemen to have similar weight and ammo capacity, with double the effective range if needed.”

            They have the range part down, but they will still need time to perfect the other two. In the mean time, 5.56 is the order of the day. Nothing particularly wrong with that.

  • Aono

    Nathaniel, I’d be remiss if I just used your articles as a springboard for my ballistic autism without thanking you, so, thank you. This is great stuff, and will be one of those primary sources future ballistic autists paw over.

  • Jedediah Pendergast

    Body armor is getting lighter and cheaper, eventually everyone’s going to be wearing rifle plates and then you’re going to want something like the 6.5 CT with a tungsten penetrator.

    • Hopefully any new round will be designed to work for both a VLD steel tip EPR, as well as a VLD Tungsten Tip EPR projectile.

      For example, if a 6.5 PCT EPR projectile is 123gr, and 40% of the projectile weight is the steel tip (49.2gr), then a tungsten tip of the same size would weigh 95.53gr – for a 169gr 6.5mm Tungsten EPR projectile.

      Curious how that would effect the weapon system reliability, range, recoil, as well as ammo loadout.

      • J

        Any? The EPR is good but there are two better constructions.

    • Johannes von’ Strauch

      Lvl4 plates holds up against 7.62x63AP (tungstencarbid) and .338Lapua Magnum FMJ. 6.5 (6.7mm) is thinner than 7.62x63AP but im not too sure if it passes trough.

      And if so… propably militarys would change to a slightly increased protection plate.

  • ARCNA442

    If the low drag 6.5mm bullets out perform 7.62mm by such a margin, should we be looking at doing the same with 5.56mm and make the next carbine cartridge something like 5mm?

    • Johannes von’ Strauch

      With 5.56 CT you get 8gramm (with better case 7gramm), with better projectile shape a really high supersonic range. +even less recoil due to less propellant use.

      At 5mm the pressure becomes really high/ or with normal pressure energy gets low.

      = you dont need to use 5mm, an full optimized 5.56CT is already light enough and has good performance, with less recoil.

      • Joshua

        M855A1 has a tendency to make good days go bad.

        Honestly instead of LSAT(at least with the way it’s going).

        I would rather see something like the KAC LMG loaded with m855A1 replace the m249

  • XT6Wagon

    I think my choice would be to stick 5.56 ammo load weight, and improve performance as much as possible while doing so. This way its an easy sell convert all lighter arms to this as its going to be an impossible sell to increase the weight soldiers have to deal with. Might be some systems savings if a shorter OAL can cut the action and magazine weight.

    • Johannes von’ Strauch

      absolute correct
      And its not just about weight, also even compared to max velocity M855A1 EPR its 167% Recoil Impulse and 281% Recoil Force. Which makes a large diffrence in urban combat (because people arent paper targets on a range standing in the open..).
      And less capacity is an insane step backwards too.

  • gunsandrockets

    Indeed, why not a better bullet than the 5.56mm.

    The 6.5mm bullet obviously was chosen for the MMG application. But for a LMG application I think something like the 6mm bullet of the US Army XM235 SAW from the 1970’s would be a better jumping off point.

  • noob

    Anybody got an explanation for what that weird hump under the 6.5ct carbine handguard is? I can see the gas piston on top so is the hump for the ejection port of a falling chamber design?

  • Aono

    Good points, and I agree with you on all of that. However I am thinking more along the lines of an MP7 or particularly a B&T USW, something that can be shouldered OR fired like a handgun AND fit in a holster. The holster requirement is, in my mind, really what dictates a conventional handgun style layout with the magazine in the grip, though it’s very possible that something more like the P90 would lend itself very well to the kinds of chamber designs required by CT (revolving, rotating, etc). Imagine even something like the Boberg pistol, which might benefit greatly from a robust CT cartridge where crimping is not a concern.

    Swappable barrel lengths, silencer options, and removable stocks, and perhaps a 300blk style subsonic cartridge (w/ barrel swap) would be available. That subsonic cartridge/barrel may then be what the end user opts for when running this PDW in a handgun barrel length configuration. The same round that the belt fed fires would be more likely to be used when running it in more of a Sub2k/CX4 carbine configuration.

    But the context that I’m advocating all of this in is one where one of the three primary NATO small arms calibers 9mm/556/762 MUST be sacrificed on the altar of standardization. The dimensions of 556CT are already so close externally to 5.7×28, a 9mm killer, that it seems like 9mm should be the one to be left by the wayside. A PDW requirement is I think going to become more and more likely as unconventional primary weapons like grenade/rocket/missile/anti material/drone jamming proliferate.

    TLDR: I would rather see 5.56CT squeezed into a PDW than 6.5CT squeezed into a carbine.

    • Renato H M de Oliveira

      Sound reasoning.

  • Wow, you woke up today and really ate your cornflakes, didn’t you?

    That was really an excellently reasoned, well-though-out, well-informed comment. Thank you.

  • I’m re-reading this over and over. It’s really an awesome comment, probably the best I’ve ever gotten. Would you be interested in turning it into a guest post here in the blog?

    • ostiariusalpha

      The best you’ve ever gotten is apparently just another rambling internet rant arguing against a strawman. You need to raise your standards, Nate. (Yes, I ate nothing but salt this morning.)

      “Tactics and operational intent should drive weapons design. Period.”
      “Tell me how you intend to fight, and then I’ll tell you how you need to design your weapons.”

      These are patently idiotic statements that ignore the fact that new weapons more often than not create a demand for new tactics and strategic planning: the machine gun and motorized cavalry were not created to fulfill the goals of blitzkrieg tactics, it was the other way around. The combat cars, battlecruisers, F4 Phantoms with no machine guns, and supersonic bombers were each the brainchild of trying to fit weapon design to projected tactical paradigms that ended up being complete illusions. A new weapon doesn’t have to create a whole new tactical paradigm, but it’s not a mistake to push the boundary and explore weapons with that potential. And if a new weapon paradigm is created, it can undergo refinement to better suit design with tactics, but that’s not the nuanced position that takirks seems particularly interested in. Yes, there are also plentiful examples of badly implemented whiz-bang gizmos, such as the 5.56/M16A1 or XM25, but even in their failures, they pointed toward better designs and newer tactical thinking. F. Corgi wants design to trump any current tactical needs, and takirks demands that tactics totally constrain design; they’re both simply wrong.

      • Johannes von’ Strauch

        Yes i know what you mean.
        But overall the 6.5CT is far to heavy with insane recoil for a carbine. Compared to even max loaded M855A1 EPR its 167% Recoil Impulse and 281% Recoil Force.
        In Urban combat with really small presented targets this makes a big diffrence.
        <1850J will let explode skulls, shred organs, shatter bones and shred arms/legs any day. But with higher % hit propability, less weight, more mag/pouch capacity.

        6.5CT will sicnificantly increase weight, decrease % hit propability in urban combat, decrease capacity. /Or with normal weight load, a lot less rounds to carry = less supression fire = no fire superority. And less time to stay in combat without running dry.

        And at range… it gets beaten any day by better configurations, with sicnificantly reduced weight, flatter trajectory, more mag/pouch capacity. And even higher supersonic range….

        • ostiariusalpha

          For current tactical needs against largely unarmored insurgents, you are correct; the 6.5CT carbine is only suitable for a DMR. But if you run into an opponent that is widely fielding decent body armor, you’ll be glad they invested in developing a platform that can punch through with the right AP round, even if you lose select-fire and quick target reacquisition capabilities. And what exactly are these “better configurations” that you think are out there?

          • Johannes von’ Strauch

            … Lvl4 holds 7.62x63AP (tungstencarbid) and .338LapuaMagnum FMJ.
            6.5 (6.7mm) is thinner, but im really not that sure if it makes it trough.
            And if… any 1st world military will slightly increase theyr armor.

            And than again……. 6.5CT is worse against armored opponents because it doesnt get trough, has stupid recoil, low capacity, and lower % hit propability to hit unprotected areas.

            +… how about simply using a damn burst? CT chambers can shoot 2200RPM without a problem.
            So in close quaters against 1st world military, you just switch to burst and pierce trough with ease…

            And, sorry but im not sure if i should go into high detail in the interwebs about it.

          • ostiariusalpha

            I’m not talking about a 1st World country, I’m referring to Russia, to be blunt. And there weight penalties for making even lightweight boron carbide armors thicker and thicker, which is why new materials are being researched (despite that there is no immediate tactical need for them. Heh!) .338 bullets, even in CT form, have actual weight and capacity limitations, unlike your exaggeration of the 6.5 CT which is 15.4g versus 12.3g for M855A1. I was also going to bring up the burst rate of the CTSAS carbine, as a 2-round burst of 6.5 CT is easily manageable; and more useful than a lighter bullet also. And no one is sure about any of this stuff, that’s why it should be evaluated in the first place. Lastly, there is no point in playing coy about firearms design, there’s nothing that you know that someone else’s engineers hadn’t at least considered, or intelligence agency hasn’t dug through.

          • Johannes von’ Strauch

            Well 15,4gramm to 12,3 = 125,2% = 167,7 Rounds compared to 210Rounds. + heavier Rifle = even less rounds for the same weight.

            Again compared to even max loaded M855A1 EPR its 167% Recoil Impulse and 281% Recoil Force.

            So why use a 2round burst with 6.5 (6,7mm) to get trough lvl4.
            Instead a 3 round burst of a lighter round. While heaving much more ammo for supression (fire superiority), able to stay longer in combat, less recoil for higher % hit propability in urban areas, more mag/pouch capacity.

            With a really well designed round you get to 8 to 9grams, = 322 or 287 rounds, instead of 167.
            =you have a drastic fire superiority diffrence
            And still have 1200m supersonic range & flat trajectory.

          • ostiariusalpha

            There’s a reason that military firearms designers don’t go with small caliber rounds that perform as you’ve suggested; they’re all barrel burners. This round has to work in a machine gun, J, and the 6.5 CT is already pushing the limits of acceptable heat flux. You might have a wonderful cartridge there, but it’s not going to be adopted.

          • Johannes von’ Strauch

            I know what you mean, but no, theyr not barrel burners at all, what are you telling me? Im not some random noob, this is my life and i know well what heatflux is, i calculate everything to the 10th decimal place. And what do you think 3333J out of a 6,7mm bore from a carbine is…. thats what i call a barrel burner.

          • Johannes von’ Strauch

            + the long bearing surface of the 6.5 that further increases pressure and wear, just because they want to get theyr 8gramm, which makes the nose shape terrible.

          • LilWolfy

            CT doesn’t have a throat like an 1800s design with metallic case. The polymer heat sinks a lot of the plasma conversion that is normally absorbed into the chamber and throat of an 1800’s design.

            The front polymer plug seals the front, and acts as neck tension for the projectile, while also absorbing a lot of that plasma conversion and flow.

            I would be very interested to see what the barrel life is on these LMGs.

  • Aono

    To your point about accessories here, one very good reason NOT to replace 5.56 with 6.5CT is that the weight growth in optics and illuminators and silencers being attached to guns that were not initially designed around them needs to begun to be mitigated. These things already contribute to extending the effective range of the weapon (just like your tripod example), arguably more so than any caliber change ever could, especially with regard to optics. But that weight then needs to be clawed back, not exacerbated. I’m not saying that a 6.5LSAT isn’t a good replacement for a 249 in the context of PKMs (which is I believe what you were getting at), only that it’s not necessarily a good replacement for an M4 in the context of that accessory growth.

    • LilWolfy

      Accessories are the past. The future will be something much better.

  • A Fascist Corgi

    To me it seems like you’re suffering from fighting the last war syndrome. The conflict in Afghanistan is a waste of our time. Designing our weaponry around that conflict is idiotic. The only conflicts that we should really be planning for are large-scale conventional wars with other superpowers. In those types of conflicts, identifying the enemy isn’t really a problem because he’ll be wearing a uniform and collateral damage won’t be your primary concern. And whoever has the most range and accuracy will have the advantage. That’s probably what the U.S. is concentrating on here with this program.

    I also don’t think that it’s a bad idea at all to focus on advancing weapon technology and adapting tactics to those weapons. New weapon technology expands what you thought was possible and dictates how you fight.

    As to the threat posed by Islamic terrorism; there’s much more logical and effective methods for dealing with that threat than insanely wasteful hearts and minds/nation building projects in countries like Iraq and Afghanistan.

    • “And never forget that soldiers are ultimately supposed to be disposable.”

      Besides being deeply immoral, that attitude is incompatible with maintaining morale in any army, let alone an all-volunteer one.

      • A Fascist Corgi

        There’s nothing immoral with realizing that you need to sacrifice soldiers in order to win a war of national survival.

        Is it immoral for a general to send his troops into a battle that he knows will result in a lot of them becoming permanently injured and killed? Of course not. That doesn’t mean that he shouldn’t care about the health and safety of his troops, but winning the war must always come first over preserving their lives. That’s his job as a general and their job as soldiers. Doing anything less than that is immoral because ensuring the safety and independence of your people should be your primary mission in life.

        And the willingness to sacrifice your life is what makes military service honorable. If you’re not willing to sacrifice your life, then why should military service garner any respect from the public? Accepting the sacrificial nature of your role is why people respect combat veterans. Without that conscious acceptance of sacrifice, being a combat veteran is as honorable as working a desk job.

        And if your soldiers aren’t willing to sacrifice their lives, then they weren’t good soldiers to begin with.

        I’m also not going to both refuting your “humanpower” argument in detail again. We already had this debate several months ago. You exaggerate how immobile a soldier will supposedly become if you make his rifle 1.5 pounds heavier and his ammo loadout 3.5 pounds heavier. And if adding 5-ish pounds to a soldier’s loadout really does become a problem, then commonsense solutions will suffice – such as abandoning or redesigning non-essential pieces of gear.

        • LilWolfy

          We don’t have the demographics to support attrition warfare on our side, and neither do many other nations. Population growth has mostly been from elderly living longer, while birth rates are declining.

    • Johannes von’ Strauch

      For you again: Overall the 6.5CT is far to heavy with insane recoil for a carbine. Compared to even max loaded M855A1 EPR its 167% Recoil Impulse and 281% Recoil Force.
      In Urban combat with really small presented targets this makes a big diffrence.
      <1850J will let explode skulls, shred organs, shatter bones and shred arms/legs any day. But with higher % hit propability, less weight, more mag/pouch capacity.

      6.5CT will sicnificantly increase weight, decrease % hit propability in urban combat, decrease capacity. /Or with normal weight load, a lot less rounds to carry = less supression fire = no fire superority. And less time to stay in combat without running dry.

      And at range… it gets beaten any day by better configurations, with sicnificantly reduced weight, flatter trajectory, more mag/pouch capacity. And even higher supersonic range….

      • A Fascist Corgi

        Welp, it doesn’t make sense to equip your soldiers with M4s when the majority of combat will take place at long range, and it doesn’t make sense to equip your soldiers with 6.5CT when the majority of combat will take place at close range. That’s why I think that the U.S. military should equip soldiers with two rifles and train them to use both.

        If the combat environment is urban warfare, then I’d want a bullpup equipped with a short suppressor and chambered in something like M855A1 or M193.

        If you’re fighting in mountains, then the 6.5CT makes a lot of sense.

        If the U.S. military doesn’t want to do that, then they should go back to the drawing board and design a new rifle + cartridge that does a better job of finding a compromise between the 5.56 and the .308.

        • Johannes von’ Strauch

          M193? wtf ints nothing compared to M855A1 EPR.

          And why two Rifles if a well made round has 1200m supersonic range, flat trajecory and light weight & medium recoil at the same time.
          I have the feel they put the diameter to “6.5” (6,7mm) because all the known 6.5 and .264 rounds, but its not the diameter that makes them good but just that theyr not as stupidly thick as 7,62×51 for theyr weight. And then tought ~8gramm sounds good (~123grain). Which results in a stupidly bad form factor. And then …had to push it to barely go 1200m supersonic… which requires so much Energy that recoil becomes insane for a carbine.

          Your last sentence is correct, a better configuration will be more fitted.

          • A Fascist Corgi

            M193 works great as long as it’s moving fast. That’s why I paired it with a bullpup for urban combat. You still get a 16+ inch barrel, and your targets should be within a couple hundred meters. M193 would perform quite well under those conditions. Go look at the ballistic gel performance to see for yourself.

          • Johannes von’ Strauch

            …M193 is verry depending on angle of attack for tumbling (icepicking trough arms and legs), sucks at barriers, doesnt go trough lvl3+

            M855A1 EPR fragments/segments instantly (and can fragment out to 600m), is better against barriers, steel, is additionally better at longer engagements.

            Well, what would work best is a M855A1 EPR light variant. 50-55grain, basicly M193A1 EPR. Due to increased velocity it would zip trough steel incredible well, and has more chamber volume +less bearing surface for better short barrel performance.

    • LilWolfy

      Every major military power in the world watched Gulf War 1, then Gulf War 2, and realized that attempting to go toe-to-toe with the US with conventional forces is an exercise in futility.

      They have all gone asymmetric as a result, where light infantry engagements become more important since the battles are fought in urbanized areas, with a lot of collateral damage likely if you use artillery, mortars, and bombs.

  • gunsandrockets

    Hi K,

    First comment to TFB?

  • Warren Ellis

    Is there any idea on what the bullets themselves will be like?

  • Colonel K

    I wonder if they’ll develop a scaled down version of this concept using a 90 grain 5.56 projectile. It might get the weight under that of the existing M4 and LMG platforms without reducing combat load or increasing recoil impulse. But will it provide the 1200 meter performance they desire?

    • Johannes von’ Strauch

      Bs, 90grain 5.56 is not possible with EPR.

      Also… KE=1/2m x v² while p=m x v => slower heavy projectile has more recoil for the same energy.

      Also at 90grain out of this bore diameter the pressure would be too high for adequat velocity. = you never get 1200m supersonic range

      More weight is a really bad idea to increase BC, shape is a far better way. With a good shape and medium weight you get normal recoil, far flatter trajectory, sicnificantly higher supersonic range, and also better angle of attack at range.

      • Colonel K

        I’m not sure I follow your reasoning. I agree a 90 grain 5.56 bullet would generate more recoil than a 55, 62, or 77 grain 5.56 bullet, if similar velocities are being achieved, but the comparison I was making was with the CTSAS 6.5 bullet at 123 grains. I don’t see any reason the CTSAS concept can’t be applied to a 90 grain 5.56. It is a long bullet with excellent BC, and unlike a lighter bullet of the same configuration, it will perform better at extreme range because, while all bullets shed velocity, they don’t shed their weights. BC can be calculated several ways, but all of them essentially involve mass (weight), cross section, density, length, and drag. I would not discount any of these factors, but try to maximize them all.

        • Johannes von’ Strauch

          1: Lead is way to soft for penetration, and even with penetrator head infront it will just spread sideways waisting a ton of energy.

          2: Volume scales up and down with ³ , which means a 123grain 0,264″ EPR projectile is 75grain at 0,224″ diameter…

          3: The 6.5 bullet already has a stupidly bad form factor, which is not what you want for good performance.

          4: It propably will be lower than 75grain because it have to be shorter for the same twist rate, due to the gyroscopic diffrence.

          5: For the same base Energy a better Form Factor will always greatly outperform heavy & bad form factor rounds, in trajectory, time of flight, recoil, and by a sicnificant amount in supersonic range. And… due to the flatter trajectory it actually passes LESS air… which means it will actually retain energy surprisingly well at range.

          I do this every day, just trust me.

          • Johannes von’ Strauch

            Also youre wrong with your units. Its (Weight : (Diameter x Diameter) : 7000) : Form Factor

            Nothing with lenght.

          • Colonel K

            I am not discussing the M885A1 enhanced performance round, but instead am addressing the feasibility of developing a 5.56mm CTSAS round that might meet the Army’s 1200 meter requirement, yet still allow for a soldier’s combat load weight to be equal to or lighter than the current standard, but with a recoil impulse that is less than that of the 6.5 CTSAS. If you believe the Army is going the wrong direction with their test and development, there’s no point in telling me. I’ve been retired for ten years. Contact the CTSAS program officer, Mrs. Kori Phillips, and pass your concerns to her.

          • Johannes von’ Strauch

            You dont need to pass any concerns, if have contact to her too.

          • Johannes von’ Strauch

            *oh ive misread it, i did read at first you contact her

          • Johannes von’ Strauch

            Yes it goes in the wrong direction, and its good to hear youre concerned for a better round.
            I just wanted to correct your thought of a magical 90grain 5.56 , because it is technically rather unrealistic and will perform utterly bad.

  • A Fascist Corgi

    If increasing a soldier’s assault rifle to 8 pounds causes him to die, then gym class was probably too dangerous for him in high school.

    • crackedlenses

      You misunderstand. I’m saying that with your philosophy concerning the use of said soldiers most of them won’t live to have any physical problems related to excessive weight.

      My second point was that since not overburdening our soldiers is no longer a concern, why would you settle for a measly rifle upgrade? Why not add more crew-served weapons to the rifle squad? If we expect them to “screw up their knees and backs when they get
      older”, I want them to have done it humping heavy machine guns and AT weapons, not battle rifles or 6.5 mm. assault rifles or what have you.

      If I am going to be overloaded, I want to be overloaded with the maximum firepower we can carry without dying on the spot. 7.62 mm. rifles alone aren’t enough.

      • A Fascist Corgi

        On the contrary, equipping our soldiers with underpowered rifles is more likely to get them seriously injured or killed.

        I’ve read about and seen combat footage of the 5.56 round failing to incapacitate enemy soldiers. I remember this one story in particular where a U.S. soldier shot an Iraqi insurgent at very close range with his M16 in the early days of the Iraq war. He thought that the insurgent was toast because he shot him several times in to the torso. While changing out his mag, the Iraqi shot him in the armpit with an AK which hit his spine and crippled him for life.

        I’ve also seen several combat videos of U.S. troops getting pinned down by accurate PKM fire from several hundred yards away. They were completely helpless. They have to wait for Apache attack helicopters to save their skin. Or they’ll rely the 1 or 2 guys in their base who have weapons that are capable of shooting back.

        And I’m not advocating that we equip every soldier with an M134. I’m simply saying that it would be equip our soldiers with 5.56 bullpups if the combat will mostly take place in urban settings, and some kind of high BC long-range rifle with a magnified optic if the combat will mostly take place at long range. Or we could simply develop a new round which has an ideal balance of BC, velocity, and weight. Why would that get soldiers killed? It should have the exact opposite effect since a good offense is a good defense. Being able to suppress and kill your enemy will make it harder for them to shoot back at you.

        • ostiariusalpha

          Actually, people do survive .308 bullet wounds. During WWII, U.S.G.I.s would regularly complain that German and Japanese soldiers wouldn’t die from being shot with the M1 Garand’s .30-06, and needed to be shot several times to incapacitate them. Our ol’ buddy, fleet yaw, wasn’t well understood at the time, but if a .308 FMJ bullet doesn’t tumble during its terminal stage then it creates a rather marginal in-and-out wound. Larger caliber bullets suffer worse fleet yaw effects at close range than smaller calibers (though you have to take bullet length into account also).

          • In reverse, plenty of Allied troops survived 0.323″ rifle projectiles during WW1 and WW2.

          • ostiariusalpha


        • LilWolfy

          You read some accounts. They are not representative of reality across larger samples. 5.56 is still preferred for the close-range fight, not 7.62 NATO. The newer projectile designs have increased its lethality noticeably, but I didn’t see a problem with it before, and I have seen numerous fatalities and serious injuries caused by it while in the military across multiple deployments.

        • crackedlenses

          That was a long one, whew.

          I’m realizing that you are relying on what you read and not on personal experience or those who have personal experience. Thus, most of what you write is your opinion. I’m in the same boat, but I’m on the other end of the spectrum.

          I haven’t researched this, but I have this quote:

          “There’s a great book out there, Shooter by GySgt Coughlin, a highly decorated scout sniper, where he talks about shooting one guy 2-3 times with Lake City Match [.308] and the guy keeps moving.”

          So no, I have in fact seen references to people taking multiple hits from .308 and still coming.

          As a response, I’m pulling another quote from my notes:

          “You also have to understand exactly what is better: number of hits, mean rounds to failure, and even more importantly, it has to be easy to support in the overall industry of making guns and ammo.

          Number of hits going up? Cartridge design won’t provide it, optics did. All thats left is training. Since the actual engagement range is 500 m., and you only need 2 MOA, most of the cartridge fanboys just don’t get it – the 5.56 does the job removing the fight from someone shooting back. You don’t need to knock them off their feet and dismember them, and those who don’t understand that are starting off with the wrong perspective.

          Mean rounds to failure? Name the acceptable limit, because if you don’t, it’s impossible to make a gun to that standard. Don’t forget, it’s the magazines, ammo, and operator error on the top three of “OMG the gun jammed!” Not how the bolt is actuated. They ALL work good enough.

          Exotic materials or new cutting edge design? Not happening. We need something easy to make, that solves problems, not creates new ones. Wonder why the LSAT is still out there, going into the test phase at Battalion level? Because it’s a simple, easy to make design, and it delivers something none of the other cartridge fanboys can deliver – MORE AMMO. It does it by throwing out the biggest piece of dead weight, the brass case. Now a soldier can carry 40% MORE AMMO, which means up to 40% MORE HITS, and that means 40% MORE ENEMY DISABLED, which means 40% MORE BATTLES WON.

          It’s not about superior down range accuracy at 600 m., or more power at 200, it’s about 40% more bullets flying around getting more hits. And those who don’t know that soldiers are hit by bullets that were never specifically aimed are clueless. It’s NOT what some want to believe, it’s what IS happening that counts, and unaimed fire causes 50% of the casualities. If you want more hits, fire more ammo. If you want more ammo, make it lighter.”

  • LilWolfy

    If you read the other installments, you see that their main goal was to simply focus on one thing: reducing soldier’s load. They pulled that off in droves with 40% reduction in the weight of linked 5.56, and increased performance, while increasing reliability due to the way the system feeds, and also used constant recoil, which is extremely easy to hit with if you’ve never tried it.

    Because their original goal and serendipitous achievements were realized, they expanded into increasing the effective range while reducing weight with another caliber. If you read between the lines, they are over-matching the ballistic potential of 7.62×51 and 7.62x54R systems, while providing another capability I won’t discuss.

    The LSAT has been vetted in operational field testing with an Infantry Platoon element at Fort Benning, along with other weapon systems, and the 11B soldiers with deployment experience prefer it over the SAW hands-down. 10lbs have been cut off the gun alone, with much smoother recoiling characteristics.

    Of all the boondoggle weapon systems we have, this is the last one I would ever dump criticism on, and I can pull up a chair and go through the failures of most of our service rifles and machine-guns. I see nothing but promise with this system. Because of the capabilities of LSAT, it could totally revamp the MTOE of the Infantry Squad. When I see how light an LMG is, and how much less recoil it has than an M4, with 200rd nut sacks and high reliability, I’m going to ask the next logical question: Where is my Commando Barrel variant?

    Another thing that I thought was interesting was that one of the testers commented that when several of their KAC M110K DM/CSASS carbines were down for maintenance, they pulled the optics off them, and mounted them to some LSATs, then proceeded to see very high hit probability with just the 5.56 system out to 800m on the transition range.

    Now imagine a 6.5mm LSAT pushing a 123gr A1 type projectile (these already exist for 6.5 Grendel) at 3000fps, with a G1 BC in the .620 region. Bye bye 7.62 NATO. You have 2000m effective range capability with that combination, as recently demonstrated with a new 122gr Warner 6.5mm, which was tested for BC accuracy out to over a mile.

  • Johannes von’ Strauch

    *its the short nose ogive which f***’s up its long range performance

  • CavScout

    So basically, all this GWOT money was getting thrown into committee land where managers just tried to manage. I bet many ‘alignment meetings’ were held.