Chambering the Next Round, ARES Working Paper

Armament Research Services has introduced its latest Working Paper, “Chambering the Next Round: Emergent Small-calibre Cartridge Technologies“, as published by The Small Arms Survey in Geneva, Switzerland. The author is N.R. Jenzen-Jones, the current director of ARES.

The report is mostly focused on two main points, that of a general purpose infantry cartridge, and the next generation of military ammunition, whether that be caseless, semi caseless, telescopic, or polymer cased rounds. If you don’t have an understanding of the advancement of military cartridges in the past century, and would like to learn more, Jenzen-Jones has an excellent background from metalic rimfire cartridges, up to current day advances, all within the 80 page report, and well backed up by footnotes, and authoritative sources. I think most importantly, he talks of this accordion effect, that initially cartridge production was to be making rounds larger, more lethal, with longer range. This is the .30-06, the .303, the 8mm Mauser. But then World War Two happens and its this rush to make everything smaller, and more lethal at closer ranges, the 7.62×51, the 7.62×39, and then to the 5.56×45, and the 5.45×39. But then today, we are finding out that at the ranges that our militaries are being employed, Afghanistan, these intermediate cartridges aren’t working. Jones raises the point that the 300 meter battle distance is sometimes no longer the case because of the inherent terrain, but also that many militaries are adopting optical sights, and soldiers can thus shoot further, with more accuracy than soldiers before them could in battle. These are just some of the points I took away from the report, but I would highly recommend reading it to gain a better understanding of the world of cartridge development.

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Infantry Marine, based in the Midwest. Specifically interested in small arms history, development, and usage within the MENA region and Central Asia. To that end, I run Silah Report, a website dedicated to analyzing small arms history and news out of MENA and Central Asia.

Please feel free to get in touch with me about something I can add to a post, an error I’ve made, or if you just want to talk guns. I can be reached at


  • Ted_K

    ayy lmao

  • Joshua

    What I hate about using Afghanistan as the rule for combat engagements is that it ignores history.

    Historically every war since WWI has had a maximum engament distances of 100-200M. Afghanistan has been the exception to the rule, would we be changing calibers for the exception to history?

    That’s up to those with higher pay grades than me, but personally I say no.

    Because historically the next war will again see maximum combat distances of 100-200M.

    • CommonSense23

      I would say the biggest issue with Afghanistan was tactics. The vast majority of US forces decided to move during daylight hours. Instead of pressing our advantage of night vision and gps to move quietly at night where the Taliban is not going to be able to set up 600+ meters away and start hammering with belt fed weapons.

      • Tassiebush

        I wonder if IEDs and mines were part of why it wasn’t done by night? I’d presume it might be harder to see the signs of them at night. There’d have to be plenty of low risk areas though I guess.

        • CommonSense23

          Our EOD guys found probably 90% of the IEDs at night, when patrolling. Yeah IEDs suck, but the enemy cannot place them close to everywhere, can’t place them a lot of places actually. I feel its the fact that the majority of the military pays lip service to owning the night.

          • Tassiebush

            It sounds like there’s basically no reason at all to not dominate the night then. Really finding your insights interesting!

        • n0truscotsman

          “I wonder if IEDs and mines were part of why it wasn’t done by night?”

          That is a very good question, and one I asked frequently. I didn’t get a very satisfying answer, but I have heard differing ones ranging from terrain unfamiliarity, the land mine threat, IEDs, politics with the Karzai peanut gallery, and anything else in between.

          I say its mostly crap. Night time is a grand time time to be conducting counter-insurgencies. History is rife with examples.

    • Ideally what would happen is to look at all potential “likely” battlefields for emerging conflicts, and see what type of ranges are likely. Russia, China, Pakistan, Korea, Africa, Latin America – what are the ranges that would be encountered there?

      Also, given that Level IV armor is already down to $200 a plate retail, it seems that any army in the next 20 years worthy of the name will have soldiers in at least that level of protection. Any new chambering / projectile should be designed for defeating that standard.

      • Joshua

        We already have M995. Anything outside of Tungsten won’t defeat ceramic armors.

        • Will M995 defeat level IV?

          • Classified.

          • Joshua

            I will say none of our enemies have any armor that will stop M995, and none of them will for a long…long time.

          • Tritro29

            That’s an industrial question, you’re answering with theological horseshit. There are a lot of nations that can propose PPE that can defeat all sorts of threats. The actual question is would they be able to afford those PPE items. Would they even care? In any fight the sword & shield philosophy doesn’t mean that one side stops fighting because it lacks a shield.

      • Markbo

        What about the .260 Rem or 6.5 Creedmoor?

        • I have no idea in terms of increased performance, but they would definitely increase weight compared to 5.56.

          • They are virtually the same weight as 7.62 NATO, and you’d have problems making EPRs for them that were heavy enough to be a serious benefit.

          • Dolphy

            6.5Creedmoor gets 7.62×51 performance out of something that kicks like 5.56; there’s no reason to not go with it.

          • I don’t know how that would be possible; 6.5 Creedmoor launches a 140gr @ 2700 fps, while 7.62×51 launches a 147gr @ 2733 fps. Surely the recoil and weight of the cartridges must be nearly identical, and far more than 5.56.

        • Kivaari

          They have essentially been tried starting back in 1890. There’s lots of field experience with all of the 5.56mm to 7.92mm in the last 125 years. If any of them were all that much better, you would still see them in service.

    • Beomoose

      Afghanistan is not quite the outlier you make it out to be. Engagement distances are pressing outward in a number of current conflicts, look no further than present-day Iraq where clearing ISIS from a city mostly means clearing sharpshooters/snipers and IEDs.

      • Joshua

        So we combat snipers, by changing our general issue caliber?

        That’s the exact opposite of how you handle situations like that.

        • Joshua

          actually, one of the reasons that snipers and sharpshooters are, have been, and will continue to be as successful as they are is that they can strike with relative impunity from immediate return fire. A component of that impunity is the extended range at which they can engage versus most modern militaries, so extending the effective range of the standard rifleman by returning to a longer ranged cartridge closer to the old 8mm Mauser and .303 British in order to start to giving the “relative” part of “relative impunity” more ah, gravity, sounds like a good idea to me.

          • Joshua

            People just need to realize that riflemen don’t exist in a vacuum.

            We have guys with a DMR, Sniper Rifle, M240, etc to combat these threats.

            There is no one caliber for all, 5.56 is amazing from 0-300M where a general issue rifle and caliber should be designed for. You use your supporting elements for other threats, It would be a horrible mistake to issue soldiers a 600-1,000M rifle for their one and only general issue rifle across the board.

            You also have to remember Snipers have optics designed for their respective calibers and ranges, so we also need to issue 6-18x optics for those general issue sniper rifles we plan to give everyone, because unless we issue the optic to support the caliber, the caliber won’t make any difference without the ability to PID. This way snipers won’t stand a chance against us ever, however at anything below 600M we won’t stand a chance against any other weapon either.

      • iksnilol

        Eh, snipers aren’t run of the mill. + most urban sharpshooters ain’t got the distance.

    • Kivaari

      The biggest problem in Afghanistan is we are there.

    • n0truscotsman

      That and it is really needless, and the ‘problem’ you highlighted above is partially sensationalism on part of GPC advocates. Riflemen/Assaultmen with M4 carbines dont do their jobs in a vacuum. There are DMRs, Snipers, Machine Gunners, 11 Chucks, and anything else as part of ‘the system’ that do the job also, supplementing the 5.56.

  • Personally, while the trend for the next cartridge seems to be 6-6.5 mm, I think LSAT really opens the possibility for a more powerful .224 cartridge.

    The high BC 77gr 5.56 @ 2800ft is considered viable out to 1000 yards, why not bump it up to 3300 ft/s for 1862 ft/lbs energy? That would offer more power than either the 6.8SPC or Grendel, with less cartridge weight and recoil, and a flatter trajectory. A 77GR M855a1 style bullet would also be very long, providing a higher BC than lead core 77gr .224’s.

    • There’s a lot of people loudly squawking for something between 6-7mm, but I hope that if such a round is adopted it’s because a thorough determination was made that it was the lightest round that could meet the requirements – and that those requirements in turn were realistic and based on thorough research and experimentation, and not just because some PM got all excited imagining US soldiers zapping people from 1200m.

      77gr with a lead-free EPR is basically impossible, it would be too long to spin-stabilize. However, a low-drag 65gr EPR would actually gain a lot of ground vs. M855A1, even when fired at the same velocity. You could get a bullet with a .215 BC out of that, I’m pretty confident, and that alone would earn you like 200-250 meters more effective range, going by retained energy, plus another 120 meters maximum frag range.

      Versus those sorts of gains for virtually no weight increase even from a brass-cased cartridge, the 6-7mm options look a little superfluous to me.

      • That’s very interesting. Was the 65gr not adopted due to wanting to maintain similar trajectories to the original M855, or was it just slightly too long for the 5.56? Also, what is the velocity fragmentation threshold for M855A1?

        I don’t have the background for calculating ballistics and BC’s. Would bumping the velocity up to 3,300-3,400 offer much in the way of improving long range performance of this 65gr EPR, or does the velocity bleed off too quickly to offer much advantage at longer range?

        • You would not be able to stuff the bullet in question into 5.56mm, the ogive would be too long.

          Bumping up velocity would make the trajectory a lot flatter improving hit probability at longer ranges, but in terms of retained energy it wouldn’t do a whole lot.

          • Very cool. I guess the last question is whether its even possible to hit 3300fps out of a 14.5-16″ barrel with a 65gr, or does a 5.56×45 powder charge represent the max of what those barrel lengths are capable of using?

          • It’s certainly possible, although you’d probably need to be using something like the 7.62×45 Czech or .35 Remington as a parent case to do so at “normal” pressures, with a corresponding increase in weight (generally speaking the casehead is the second biggest contributor to cartridge overall weight, behind the bullet).

          • While I would love to build a wildcat AR (I’ve been pondering a .22 Cheetah AR10) I was really thinking more in terms of the new LSAT cartridge. I figured it would be fairly simple to lengthen the cartridge a bit to bump it up to 3300/ 3400+ from a 20″ barrel. A decent boost in performance, with very little increase in weight or recoil vs. going to 6.5mm.

            Since the LSAT doesn’t have a cartridge neck mouth for the bullet to seat in, I wonder if it opens up the chance of other, previously unworkable VLD profiles?

          • You still have to have the center of gravity within the shank of the bullet, so probably not.

          • oldman

            Will pushing up velocities that high not burn out barrels much faster as well as increase the need for better heat dissipation ( heaver barrels )?
            I was under the impression that the faster the bullet velocity the shorter the barrel life. I was also under the impression that the faster the bullet moves through the barrel the more heat it generates from friction.
            I am asking because i am curious if what I was told is correct or not.

          • It’s more complicated than that, but yes, the faster 5.56mm cartridge would wear barrels faster than 5.56mm.

          • Tassiebush

            Like the .224-6.8spc cartridge.

          • That would be a bit smaller, so would need to be a little higher pressure.

          • Kivaari

            It seems that anything that pokes a hole into a target is a good choice. Most of us know that going for increased FPE isn’t as important as creating a hole in the enemy, anywhere on his body.

  • Tassiebush

    I’m guessing the first caseless round on the last picture was the Daisy caseless round. Well worthwhile to read up on. It used an airgun style spring piston for ignition.

    • It was not. Caseless was being played around with all the way back to the 19th Century.

      • Tassiebush

        I mean 1st in order on the picture.not chronologically. Just looks like the Daisy caseless round. Chronologically I’d guess the nitrated cloth or paper cartridges would be first caseless.

        • Oh. Herp derp.

          • Tassiebush

            Haha I actually initially thought you were telling me that it was a 19th century caseless round so we can form a herp derp support group 🙂

      • Tritro29

        Err We actually started with caseless munitions. Like since the begining of fire arms.

        • Those were not self-contained cartridges, however.

          • Tritro29

            The pedantic me wants to underscore the fact that the first fire arms (the “firelances”/”Dragonmouthes” etc) were actually simply self contained ammunitions lit up to make a bang.
            The normal me agrees and moves on.

  • Kivaari

    If it were up to me, and nothing is up to me, I’d stick with the M4A1 carbine. The M4 fulfills its role quite well. An effective DMR in the mix along with support weapons like arty and mortars and air delivered ordnance works well. The enemy in Afghanistan doesn’t have an edge when it comes to rifles and belt fed machineguns. We have more to fear from poorly planned FOBs and sluggish command decisions. It would be nice to have a rifle that was very effective at 500 meters, but it just isn’t enough of a reason to replace existing weapons. Look at where most of our fights take place. Lots of up close and dirty fighting has been going on since time one. Remember that most of the fighting in WW1, WW2, Korea, Vietnam and then the cities and graveyards of Iraq.

  • The problem with caseless ammo is the lack of ability to take some of the heat from the chamber with the ejecting round.This coupled with the fact that a metallic case just makes packaging against the elements that much easier. Of course failure to fire also is more easily solved with a metallic case when it come to pulling the round out of the gun for malfunction clearance. Granted this is usually addressed by adding a type of extractor groove int eh caseless round but you always have more probability of going from a minor malfunction to major gun permanently down malfunction with caseless ammo.

    • BattleshipGrey

      These were some of the thoughts I had as well. Even if someone comes up with a reliable caseless cartridge, it’ll take a LOT of testing and trails before people will come to embrace it.

    • Luke

      All of the heat in the chamber comes FROM the metallic cartridge transferring the heat of combustion to the chamber in the first place. Something like the LSAT case telescoped round, or even a conventional polymer cartridge doesn’t transfer the heat to the first place. The chamber simply doesn’t get hot enough to cook off a round. As a by product, polymer cased rounds can get away with slightly less powder to launch the same projectile at the same velocity. There is less energy getting converted to heat.

      • raz-0

        SO you are telling me the chamber is NOT of the same piece as the barrel with hot, expanding, burning gas in it, and that even if it was, that material does not conduct heat?

        Have you ever seen a gun? I’m pretty sure that if you can set the handgurads on fire/melt them (depending on what type of rifle you are shooting), that the chamber might just get a wee bit hot being cut into the actual barrel that has gotten hot enough to do that.

        • zxcv

          Not him, but the chamber on the LSAT is separate from the barrel.

        • ostiariusalpha

          Yes, that’s what he is telling you. The chamber on an LSAT is indeed separate from the barrel, you also made the mistake is in ignoring his point about how polymer cased ammo insulates the chamber from having the heat of the propellant ignition conducted into it. There will still be some heating, the polymer cannot perfectly insulate the chamber and the hot gas transfers heat to the barrel (though, on a traditional metallic cartridge, the heat transfer is focused primarily in the chamber).

        • Luke

          AFAIK, no one has yet been able to get a gun firing ammunition with a polymer case to cook off. There simply isn’t enough heat transferred to the chamber, even in something like an M4 or M240. The M2 has gone to 4 times the standard cycle for cook-off of brass rounds with polymer cased ammo, and the chamber was cool enough to not burn your finger.
          OTOH, I do not believe that anyone has yet tried to get something like an M240 to the red-hot barrel stage.

      • First my post applies to caseless ammo not polymer cased ammo.

        Luke, think of it this way. When the powder fires it is doing so inside a chamber. With a cartridge case the chamber is yanked out and thrown over board each time the gun fires where as the case less transfers all that heat directly to the gun without any heat being absorbed by a cartridge case that is tossed over board. This is a known phenomena with case less vs cased ammo that has been a hurdle to case less ammo from day one. Cook off has been a serious issue with case less ammo as well since there is no cartridge case to have to heat up first to before it gets to ignition temperature of the powder.

        • Luke

          You are correct. Caseless ammo is going to have the problems that you describe. ALL of the heat generated by the combustion is going straight into the chamber, and there is no way to extract it.

  • Jay

    Most people who disregard a unified cartridge idea, think from the civilian shooter perspective, or at best, from the rifleman’s perspective and completely ignore the major role the machinegun plays in the unit.

    • n0truscotsman

      The unified cartridge idea sounds wonderful in theory, until the numbers are calculated out and harsh realities are confronted, then it is quickly realized it creates new problems for every one that it solves.

      Only theoretical technocrats have ever messed with the GPC idea. Those with real life experiences in the matter have an entirely different opinion, especially those former infantry NCOs of us that *DO* (aughta) know a thing or two about the role of machine guns.

  • Tassiebush

    Yep that’s it. A pretty novel idea. I read that ammo was made using a propellant that was a byproduct of propellant manufacturing so it was very cheap potentially.

    • It’s a really cool idea, and given the shortage of .22lr due to the inability to produce enough rimfire cases, this really needs to make a comeback. I wonder if this type of projectile would work in a semi auto? Assuming the propellant is durable, it would solve the problems with rimfire ammo binding up in double stack magazines. Plus without being limited to a given tiny case, a .22lr sized cartridge could likely be bumped up in the power department.

      A caseless .22 40gr @ 2000fps would get plenty of folks attention.

  • burner

    we have already tried caseless rounds with black powder ha ha