Should the Next Rifle Be a Bullpup? Honest Accounting Applied to the Rifle-Ammunition System

Original caption: "Peruvian Marines armed with standard configuration F2000s in July 2010." Image source: commons.wikimedia.org, public domain

In three previous articles, we briefly discussed some of the tradeoffs involved in the bullpup concept, and some of the challenges they face in the field of military procurement specifically.  Today, we’re going to continue this deep-dive into the bullpup concept by examining how the selection of either a bullpup or conventional layout affects concurrent development of a new ammunition system. In other words, we are going to address the question: Given the same performance requirements, how does having a longer or shorter barrel affect the characteristics of a new type of ammunition?

To do this, we need a couple of tools. The first is the method I outlined in an October of 2014 post on modeling cartridges cases in SolidWorks. The second is an online Powley computer for controlled performance estimation. In addition to that, it’s handy to have calculators for recoil impulse and platoon ammunition weight, as these will be the two chief elements affected by the different sized ammunition we will be modeling.

Now, for the purposes of example, we will need an ammunition performance baseline. In this case, I chose the “General Purpose Cartridge” configuration proposed by Anthony G. Williams, since it’s a mid-sized round and makes platoon ammunition calculations easier. His concept calls for a 108gr (7g) .264″ (6.5mm) projectile fired at a muzzle velocity of 2,770 ft/s (845 m/s), therefore those are the figures our rounds will have to meet. I also opted to model only brass-cased rounds, as that was easier and would also magnify the weight disparity between the rounds. Finally, I needed to choose a set of barrel lengths. 20 inch barrels seem reasonable for bullpups (and are preferred by Williams as per his concept), which allows us to derive an equivalent barrel length for a conventional rifle. The bullpup layout generally allows an additional 6-8 inches of barrel length for a given overall length, but this assumes a conventional with a full-length stock. Since most modern conventional rifles sport collapsible buttstocks – a feature essentially incompatible with modern bullpup designs – I used a penalty of 5.5 inches for conventional rifles. This gives us a barrel length of 14.5 inches. It is also reasonable to suggest that a military force may be comfortable with a slightly longer barrel (e.g., the USMC’s M27 IAR) if improved performance followed, so I also did the calculations for 16.5 inch long barrels.

With these baselines in place, it was possible to model three different cartridge cases which could meet the performance requirements at each barrel length:

To create these models, place holder figures were entered into the Powley computer at a set peak pressure and the case capacity adjusted until the 2,770 ft/s velocity figure was reached. Then, a sketch of a cartridge case was created in SolidWorks for each round, and adjusted until the measured case capacities matched those in the Powley sets. To perfect each model, the Powley calculations and cartridge models were the adjusted via trial and error until their figures matched. The resulting cartridge cases are shown below:

Left to right: The 20″ barreled bullpup GPC case, the 14.5″ barreled conventional GPC case, and the 16.5″ barreled conventional GPC case.

 

For the 20″ barreled bullpup case, I used a custom case head 0.422″ in diameter at the head and 1.805″ in length. For the 14.5″ and 16.5″ barreled conventional cases, I used a case head 0.445″ in diameter at the head, and 1.910″ and 1.790″ in length, respectively. I deemed the difference in case head diameters reasonable, as it would fully illustrate the weight reduction possible with a longer barrel better, due to the reduced amount of material present in the smaller case head. With similar sized heads, the shorter barrels would have resulted in excessive cartridge overall length. For the two different sized cases, wall thickness was adjusted to maintain hoop strength of the brass. Besides the case head diameter and wall thickness, all other relevant parameters (e.g., rim and extractor groove dimensions, case taper, shoulder angle, neck length, primer size) were kept constant.

The completed case models had the following masses:

GPC-Bullpup – 119 grains / 7.70 grams

GPC-Conventional – 133 grains / 8.59 grams

GPC-Conventional (16.5in) – 127 grains / 8.29 grams

To estimate propellant mass for each round, it was assumed that propellant would be loaded at an approximate mass-volume density of 1.02 for a given net capacity. This was done because Powley does not adjust propellant load data based on pressure, and so substitute figures had to be derived.

Estimated propellant masses:

GPC-Bullpup – 35.0 grains / 2.27 grams

GPC-Conventional – 42.9 grains / 2.78 grams

GPC-Conventional (16.5in) – 38.9 grains / 2.52 grams

Using the performance and propellant figures, I was able to calculate the recoil impulse for each round:

5.56mm NATO – 1.28 lbf-sec

GPC-Bullpup – 1.95 lbf-sec

GPC-Conventional – 2.09 lbf-sec

GPC-Conventional (16.5in) – 2.02 lbf-sec

7.62 NATO – 2.61 lbf-sec

With the case and propellant masses established, complete round masses could then be derived. Note that each assumes the mass of a small rifle primer is 0.25 grams:

GPC-Bullpup – 266 grains / 17.22 grams

GPC-Conventional – 287 grains / 18.62 grams

GPC-Conventional (16.5in) – 279 grains / 18.06 grams

Using a modified version of the previously linked ammunition load calculator, I was able to account for the differences in total ammunition load carried by the platoon. I used figures of 25 rounds per magazine, 2.9 grams per link for the 20″ barreled GPC round (the smaller diameter case allows for lighter links) and 3.4 grams per link for the 14.5″ and 16.5″ barreled GPC rounds, and 150, 155, and 160 grams per magazine for the 20″, 16.5″, and 14.5″ rounds, respectively. The results were:

GPC-Bullpup – 355.534 kg

GPC-Conventional – 386.634 kg

GPC-Conventional (16.5in) – 376.022 kg

These figures together establish the degree to which the longer barrel as afforded by a bullpup layout allows smaller and tamer ammunition to be developed for the same performance. As some of our readers may have already guessed, the resulting difference does not seem to be very great. The 14.5″ barreled conventional round carries a recoil impulse penalty of just 7%, the 16.5″ barreled conventional round barely 3.5%. The penalty in terms of round mass is just over 8% for the 14.5″ round, and less than 5% for the 16.5″ round. When the entire platoon’s load is accounted for, the penalties are 8.7% and 5.8%, respectively.

This means that, versus the 20″ barrel, choosing a 14.5″ barrel as the standard for a new ammunition’s performance specifications results in an additional 31.1 kilograms (68.6 lbs) carried by the platoon, which is an average of about 0.8 kilograms (1.8 lbs) per member of the platoon. With a 16.5″ barrel as standard, the penalty drops to 20.5 kilograms (47.2 lbs) or 0.53 kilograms (1.2 lbs) per platoon member.

To add perspective to these figures, I modeled the 14.5″ barrel GPC round with a conventional steel case, instead of brass. This resulted in a case weight of just 7.2 grams, and a round weight of 17.23 grams, nearly identical to that of the 20″ barrel GPC round.

From this analysis, I leave the reader to make their own decision. If a new round is to be designed, is it worth it to accept a longer-barreled bullpup, or are the differences not great enough to justify the concept?



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 nathaniel.f@staff.thefirearmblog.com.


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  • Johannes von’ Strauch

    First, ofcourse haha. I hope its gonna get a good article – give me a second to read.

    • Johannes von’ Strauch

      As logical – less cartridge weight, less recoil, less heatflux.

  • Johannes von’ Strauch

    Reminder for everyone – Heatflux is a big deal for the Military, and a substantial part of this topic. A longer barrel (more bore surface area) and less powder will be an advantage in barrel-wear. It plays an absolute key role besides the reduced recoil and cartridge weight.

    • gunsandrockets

      Muzzle blast is another issue that shouldn’t be ignored. Which also gives an edge to the longer barrels.

      • Johannes von’ Strauch

        Yes forgot that for a second, muzzle blast and muzzle flash. Ofcourse therefore also shorter&lighter supressor for the same reduction, and more balanced with supressor.

      • Amplified Heat

        Kind of a wash, sort of, since pups have a closer muzzle in most incarnations. But for a fixed OAL, apples to apples, yeah, you’d expect a bullpup to have lower muzzle pressure/flash/noise from its longer barrel, and more efficient cartridge. Cans may be added with a much smaller muzzle weight/length penalty, which really moots the issue.

  • iksnilol

    Wouldn’t the 16″ barrel be better in regards to suppressors (sure, a slight weight penalty in regards to the ammo but still might be worth it?)?

    • AMX

      Better than what?
      Better than the 14″ – yes. Longer barrel and less powder mean less pressure at the muzzle, which means less noise to suppress.
      Better than the 20″? No. Same reason.

      • iksnilol

        I’m thinking in regards to using the bloody thing, not in regards to ballistics. 16+4 is easier to handle than 20+4, even if it is a bullpup.

        • CJS

          Isn’t a 16″ conventional the same length as a 20″ bullpup, suppressor or not?

          • iksnilol

            I was thinking a 16″ bullpup versus a 20″ bullpup.

            Sweet Geez, Louise, you’re killing me.

          • DW

            Solution: a 20″ bullpup… using Korobov’s design

            ~26″ Overall bois

          • iksnilol

            Yeah, but a Korobov bullpup with a 16 inch barrel would be 22″ overall.

          • CJS

            Yeah, sorry sleeptyping is a terrible way to live 🙁

          • No. A 12″ conventional is the same length as a 20″ bullpup.

          • ostiariusalpha

            Haha, it depends on the bullpup! You aren’t saving much length with the VHS-2.

          • Amplified Heat

            “Now with even longer length of pull!”

  • datimes

    Those F2000’s look like something out of a Star Wars movie.

    • Major Tom

      They look like something out of Halo actually. (Although the designer of the Halo assault rifle coincidentally drew up designs roughly about the same time the F2000 came about.)

      • Ben Warren

        He lamented the fact that the two look so similar, because he knew that people would accuse him of copying the F2000. But the game had shipped by that time and the MA5 series has become iconic in its own right.

    • hikerguy

      Why yes, they do. Cool, ain’t they? I am surprised they haven’t shown up it the new movies. Really.

      • ostiariusalpha

        The Panem forces used them in the Hunger Games movies.

        • Jason Culligan

          They use both the F2000 and the P90. Have to say the F2000 without the integral scope in white has some serious sex appeal.

          • forrest1985

            F2000 was also used in first GI Joe film quite a lot too

  • Zingbex

    At the same barrel length, bullpups are heavier than conventional rifles. The extra weight for a longer barrel magnifies that disadvantage. A longer barrel also diminishes one of the main advantages of the bullpup, shorter length. Using a heavier bullet with a higher BC, gives you sufficient range without the longer barrel or excess powder and recoil. If Shell Shock Technologies ever gets around to making rifle cases, the case weight is cut in half, obviating a change in rifle platform for the sake of weight.

    • Form Factor

      ?… For the same barrel length old bullpups are heavier than old conventional rifles. Not tough with a modern bullup made from the ground up, your argument is silly.

      “Using a heavier bullet” – which out of a short barrel is painfully slow, and …would be faster from a bullpup barrel.

      • XT6Wagon

        Are they? what are you basing that on?

        edit: meant to put under zingbex

        • Form Factor

          Basic physics…. A heavy Projectile will be slow from a short barrel. While faster and better performing from a longer. Also his argument doesnt make sence because the longest stable projectile is already choosen for the cartridge, and a shorter barrel means for the same twist an even less stable projectile.

          Making the projectile heavier in this case means decreasing form factor, and therefore efficiency, sure the bc is a tiny bit higher, but at extrem expense of velocity and therefore point blank range, trajectory, supersonic range, winddrift.
          And as said, projectile stability will be a further problem for a short barrel.

          • XT6Wagon

            I was talking about Zingbex’s assertion that a bullpup is heavier than a conventional rifle at the same technology level.

    • MSG1000

      Every bullpup I’ve heard about uses a piston op-rod system which adds a chunk of weight compared to DI. I’ve always wondered if that would bring one inline or close to an M4A1’s weight.

      • Giolli Joker

        You’ve never heard about the FAMAS, then. 🙂
        (Lever Retarded Blowback)

        • MSG1000

          I actually have and read about it, just forgot about the lever retarded action in the age of DI, short-stroke and long-stroke piston guns. My bad.

          Just looked it up and the FAMAS weighs about 8.5 lbs with a 16″ barrel. Does it use a heavy steel receiver or something? Seems excessively heavy for something its size.

          • Major Tom

            They pretty much threw on a lot of unnecessary (and unreliable) bits. The FAMAS is a very “special” gun and needs more accommodations than the average SJW in order to work.

          • MSG1000

            Damn, that sucks. If the French had actually kept a firearms industry they might’ve worked on ripping out that junk to lighten the load instead of having to outsource an existing design. Not that the 416 is absolutely terrible or something, just a shame a unique design was never attempted to be perfected.

      • Amplified Heat

        RDB could likely be done in DI, since gas would vent down, away from the face. That’s the main issue preventing its use up to now.

        But that would require someone choosing to use the clearly, unquestionably superior Stoner gas system in a gun that isn’t otherwise a straight AR clone. A feat that has never been attempted…for some reason. 😉

        • VieteranGunsmith

          Actually, the location of the gas port need not be any particular direction. Many piston guns run with ports above the bore, some below, but technically it could be done diagonally at 10/2/4/8 o’clock as the gas tube can be routed around the outside of the barrel and enter the upper in relation to the bcg/gas key location within the action. Stoner perfected DI, and I am not certain he originated the idea. His system is most definitely the zenith of DI in execution and has been the gold standard for decades because he worked out the optimal placement of the system components.
          Could this be incorporated into a bullpup design? Certainly, but those who design these rifles don’t seem to appreciate the DI solution. Talk about your prejudices, the only reason pushrod/piston systems are so currently topical is people who are convinced there is something inherently bad about DI. If properly maintained DI is very reliable, and having a piston system is no guarantee of reliability. Any mechanism can and will fail, so the big push toward piston systems is a step backward in reality; somewhat like the push for a 7.62mm bore weapon instead of the long proven 5.56mm currently in use. It is not the size of the projectile that makes the AK effective in battle, and the AK is not that great for longer ranges than 200 – 300 meters when it comes to accuracy (which I find many of the advocates of that caliber for our new service rifle arguments a bit comical).
          These people want the M4 gone and the M14 back from the 1950’s. The fact Bob Scales thinks this is a good move makes me question his opinion’s value and validity.
          I hope that someone in Congress has the intelligence to see that this is a stupid idea. When your adversary abandons their proprietary caliber in favor of one more like what your forces are deployed with, that is a message that bears heeding. The AK74 did not happen by accident.

      • Amplified Heat

        Were HK Design not cheap idiots, a bullpup done up in the G36/UMP polymer heavy manner could have been extremely lightweight. Alas, they cheaped out hugely on furniture & accessories, to the point that anyone familiar with them would be astonished that any alleged “wandering zero” was discernable off a flimsy plastic rail mounted plastic soda-straw “optic”

    • The Thales F90 is actually a bit lighter then every other piston driven 5.56 rifle except the Beretta ARX.

  • William

    Having been issued an m16, m4, x95, and x95L in my (Israeli) military service, I can without a doubt say that one thing often overlooked in talking about a bullpup vs a traditional rifle is their handling in close quarters environments.

    Inside buildings, in cities, boarding ships, or dense woods/jungles lends itself to bullpups so well. Less to get snagged on, easier to slice corners, the ability to present a smaller profile, etc.

    • That is an interesting perspective, certainly, but I’ve heard arguments both ways. Me, I’m unsure, and I’m happy to have each nation’s services make their own decisions on it. However, what I think is untenable is a new ammunition specification that de-facto mandates a bullpup.

      • 360_AD

        The line of questioning seems a bit backwards and odd. Ammunition should not determine the design of a service rifle. Usually it’s intended use that dictates the rifle, then if the rifle needed a specific (and economically sound) ammunition to reach its full potential… only then is the ammunition considered.

        • ostiariusalpha

          Well, historically speaking, new rifle designs were required for advances that were made in ammunition. The metallic case, smokeless powder, and spitzer bullets created new engineering demands for firearms that could handle their increased performance.

          • 360_AD

            Historically, yes. But, it’s 2017. Is there a long standing universal rule stating that we have to always do things the way things have been done or thou shalt burst in flames and perish?

          • ostiariusalpha

            Yes, history is still happening even in 2017.

          • VieteranGunsmith

            As succinctly stated by George Carlin – “History is just one damned thing after another!”.

          • VieteranGunsmith

            Actually there is a reason for time honored methods and approaches when designing weapons and ammunition – they have to work. The reason behind observing standards and practices is not a past versus future thing, it is rooted in practicality. One thing every veteran will tell you is that if your weapon and ammunition don’t work nearly 100 percent of the time, you’re dead.
            It is 2017, that is true, soon it will be 2018 and so on… Time is not a part of the equation, but success is built upon past success, because it is the most sure way forward. If you were building a car, would you spend time and money reinventing the wheel, or would that money and time be better spent designing that vehicle from a known successful pattern?
            Starting with a system that works increases the chance of success and more importantly, delivering a reliable weapon and ammunition to our troops who are fighting on our behalf around the world today in 2017 and for the foreseeable future.
            Unfortunately, true success is based on past successes, and that is how the real world works. Every innovation in the last several decades has come from earlier work by people who used this method to develop their ideas, and that is the truth, especially when it comes to firearms. There are few true visionaries throughout history, but every one of them was rooted in the technology of their time and developed their particular technological advances from examples from their past.
            We don’t have another John M. Browning, or Eugene Stoner, but we do have people who have studied their work and that is where all true progress in the engineering and design of weapons today.

        • Mike Crumling

          The proper way to design a firearm is to design it around a magazine. The proper way to design a magazine is to design it around the ammunition.

    • trjnsd

      That’s it exactly! One can figure all these math theories endlessly, but the whole purpose of the Bullpup is to make the rifle shorter and more handy! Remember the Japanese WWII rifles? Way too long.

      • 360_AD

        Yup. Form follows function.

      • iksnilol

        BUT MUH BAYONETS!

    • MeaCulpa

      Yeah, the great advantage of bullpups is the short length; the great downside, imo and all that, is the inability to change shoulders.

      • 360_AD

        Which is a moot issue if said bullpup is designed with that in mind… KelTec RDB, F2000, etc. Even some that eject to the side deflect brass forward in a way that it is not as much an issue as older bullpup designs.

        • b0x3r0ck

          I almost want to disagree with you simply because you said KelTec.

          • 360_AD

            Irrelevant. The point is not Kel-Tec’s manufacturing capacity. The point is it’s possible to design a bullpup that do not have the negatives of past side-ejecting designs. And allowing the shooter to switch shoulders with ease as necessary. However few KT manages to push out of its assembly lines, it remains a proof of concept.

            To me, the real weakness of bullpups is this: Quick access to the action when it is needed to clear malfunctions. By design, bullpup actions are closed and less readily accessible than traditional rifles. Then again, how often does is really happen in combat? More than likely, the soldier picks up another weapon, call for support or switch to side arm as last resort?

          • Amplified Heat

            It’s not like an AR chamber is super accessible, either. The RDB design is actually rather amenable to a quick release top cover that would make chamber access much easier (along the lines of the FS2000)

          • Bernd

            People often come up with the clearing malfunction thing… I had to clear malfunctions with blanks in an Austrian Army issue STG 77 (never had any with live ammo, but the blanks were quite weak) Clearing those malfs was fast and easy: Either by taking out the magazine or in other cases pulling out the barrel (which takes only a few seconds…) everthing was back running in a few seconds.

        • MeaCulpa

          I hear you, the KelTec isn’t going to be issued by any army and I suspect that the Israelis have worked around the side ejection by adopting their tacticts. Anyways I’m a huge fan of bullpups and hope that we one day might have bullpups electrically firing caseless ammunition.

          • Physic

            Theres little reason to fire “caseless”, polymer cases do 95% of things far better.

          • MeaCulpa

            Except no ejection being needed with casles ammo.

          • Physic

            CT has extremly simple and ambi forward or downward ejection. Is much more envoirment and handling resistant than caseless, needs less propellant than caseless, has less recoil, less barrel wear, and has FAR LESS chamber heating.

          • Zack mars

            Yeah, too bad about all that “physics” nonsense.

            Caseless just can’t work with our level technology

        • FactChecker90803

          You forgot the Desert Tech, MDR rifle, it has ambidextrous ejection (right and left), and it has the added feature of ejecting spend cases forward and not to the side.

          • 360_AD

            I did not forget. I just didn’t list it because it is not a forward or downward ejecting bullpup. It’s a side ejecting design and the user has to make physical alternations to change which side it ejects out of. Wth the RDB and F2k, you switch from shoulder to shoulder on the fly and ejection pattern is not even part of the equation.

          • Zack mars

            The MDR doesn’t exist

        • int19h

          The problem with bullpups that are designed around that in mind, is that downward, and especially forward ejection, generally mean that it’s very difficult to access the chamber to e.g. clear a malfunction like an FTE or a double feed.

      • RealitiCzech

        How important is shoulder switching, really? Everybody agrees it’s good to be able to do it, but actual users suggest that it isn’t that common in the real world. Shooting with the off shoulder, you may be minimizing the target you present but you are increasing the time you are exposed while taking the shot.
        Bullpups have issues beyond shoulder switching. The balance that is great for up close work is less ideal for distance work, as the weight is more supported by the firing hand than the support hand – when you need careful trigger control, that becomes difficult.

        • Surly Old Soldier

          How important is not getting shot in the face?

          That’s what happens when you have to lean way out from cover to shoot your right-shoulder-only bullpup around the left side of cover.

    • Big Daddy

      Not to mention mech troops. In a small vehicle the shorter the weapon the easier it is to use and maneuver with. I hated the M16A1 in my vehicle, terrible rifle to use in a vehicle.

      • adverse4

        Get out and walk. How many times did you shoot the M16 inside the vehicle?

      • iksnilol

        BUT VALORIOUS TOLD ME THAT ALL US VEHICLES WERE MADE WITH THE M16 IN MIND IN REGARD TO HANDLING RIFLES INSIDE THEM!?

    • Anonymoose

      And if you put suppressors (and fixed the Tavor’s leakiness) or Flaming Pig-style brakes on them you wouldn’t have as much noise either. I can see the muzzle being closer as being more annoying, just like when we went from the M16 to the M4.

    • jonp

      You beat me to my first thought on this.

      • Surly Old Cynic

        The Tavor was designed to provide a large cash infusion into IWI for purposes of Israeli domestic politics.

        • jonp

          All firearms adopted by Nations are not done in a vacuum. This does not invalidate why it was adopted. The Isaelis needed a short barreled firearm for the urban warfare they expected and the AR did not fit the bill. Enter the bullpup design

    • CavScout

      ‘Often overlooked’ ???
      That’s one of the very very few benefits, always mentioned, and highly over used.

  • Denny

    This is so far the best laid out argument for ‘advantage’ of b-pup. With minuscule of advantage in ballistics whole slew of distractions in human engineering.

  • RSG

    Shouldn’t we begin with the premise of what defeats a Sapi plate and work backwards? As an example, we know that the threshold for defeating an AR500 plate is a 556 round traveling at 3100fps. Shouldn’t our first concern be defeating enemy armor if we are going to bother creating a new round from whole cloth? Perhaps 90gr projectiles (just an example) with enough case capacity would be the ticket. Seems like case length is most important. With that in mind, we know that POF has mastered creating a 308 caliber rifle on a receiver group the size of a standard AR15 set. It also has a very similar bolt size. Seems to me that’s the route we need to go. Create a round with a very high BC, get it moving fast out of a case that yields an OAL similar to 308, but with a projectile weighing around 100grains. But what do I know.

    • XT6Wagon

      They need a round that can go more than 1K rounds before burning out the barrel. Also need to do it when subjected to full auto fire. What you describe sounds like a good way to keep a barrel manufacturer really rich.

      • RSG

        Sure, out of a standard AR platform, you’d see throat burn out fairly quick. But I suppose we are only limited by our traditions and imaginations. The ability exists to extend barrel life, we just don’t apply it. The use of an enlarged aluminum barrel nut and an abbreviated aluminum barrel sleeve could create a heat sink that would be 1000% more effective than what is used today. I’m not an engineer nor a scientist, but it’s not like we don’t know the obstacles to overcome and the best way to do it.

        • LVL4

          Hint: Barrel life is not about having some heat sink stuff, but about gas erosion in the bore.

          • XT6Wagon

            Yup, we might “cure” the issue with some advanced material technology, but as it sits, there is no way to keep shooting “hot” rounds through a barrel in the manner that the military does while being cost effective for making hundreds of thousands of guns.

            One must think of the use not only in semi-auto aimed fire like a designated marksman, but the use of SAW and LMG since no military I’ve seen can resist using the same ammo in the most possible applications.

          • LVL4

            No need for some hyper advanced material stuff, its way simpler to solve.

          • George

            Both, as really hot barrels erode more.

    • LVL4

      “Defeating” body armor …. have fun against standart military LVL4 that stops 7.62×63 AP even with extrem rare and expensive tungstencarbidecore….

      Solution -> forget about it.

      • XT6Wagon

        we could do it, its about cost. Also please forget WWII era “AP” as not being worth anything. .30-06 AP is worse at poking holes in things than commercial magnum rounds made from pure lead. Small frontal area and fast velocity are the main key to poking holes in things, might want a hardened core to get through the worst stuff, but that adds cost.

        • LVL4

          Im talking about hot loaded tungstencarbide rounds…. not ww2 era things.

          Lvl4 stops .338 LapuaMagnum FMJ at over 6600Joule.

          Also in therms of small frontal area even tough beeing advantageous, it will increase drasticly after hitting the ceramic.

          And as soon to manage to barely penetrate Lvl4 at point blank range, it wont at distance, and the Opfor army can adopt a slightly thicker plate for a bit more weight. To make you stuck with a completly overweight&overrecoiling rounds, in a heavy and low capacity rifle, with few rounds to carry and absolutly no fire superority. Good job…

    • ARCNA442

      I really wonder if it is even worth trying to defeat body armor. The current generation of armor protects very little of its wearer’s body and is aimed at protecting against lethal wounds rather than at preventing all injury. Given the rather random distribution of wounds, armor probably reduces casualties by only ~10% or so (although it probably cuts fatalities by far more). Combined with very low small arms accuracy in combat, if a weapon system that can defeat armor reduces carried ammo by more than ~10%, it would probably end up causing fewer casualties than the system that can’t defeat armor.

  • EdgyTrumpet

    Memepups again?
    You are just baiting us at this point.

  • bruce Cambell

    One might also take into consideration the military’s interest and increasing practice of using suppressors. The bullpup has the advantage here, where as the added length is not so much of an issue.

    • Also the added weight and effect on balance. When you have a suppressor, IR Laser, and weapon light all mounted, that’s 1.5lbs of weight at the end of the rifle, which increases the mechanical leverage against the shooter.

      With a bullpup, the rearward balance helps offset that, whereas with a conventional layout the rifle is just really front heavy.

      • Zack mars

        On the flip side, most bullpups are heavier than their standard contemporaries.

        • Most are, although the new Thales F90 is actually lighter than any of existing piston rifles on the market (7.13lbs) with the exception of the Beretta ARX100 (6.8lbs.)

        • VieteranGunsmith

          … and their triggers are abysmal. Not suited for any long range precision work… add to that they are just plain pig dog ugly and you get the whole bullpup picture and the reasons why they are unsuitable for use as our main battle rifle.

          • Amplified Heat

            LOL at people who (probably) think an AR is pretty, even though is has more weird tumors growing on its sides than a Krag. The triggers have sucked since most pup designs on the market predate the “precision trigger in a service rifle” movement that placed proper importance on this function. Now we have the RDB with a very acceptable trigger, and perhaps one day the MDR with an allegedly excellent trigger. A lot of older traditional rifles had poor triggers as well, and a lot of the military pups had poorly converted semi-auto designs that retained the bad pull of dual-phase trigger systems.

          • iksnilol

            “they are ugly thus no good”

            Now I see why your username is misspelt. Also, most military rifles do have crappy triggers.

        • Amplified Heat

          Even though there is no reason for this. It’s not like the handguard or receiver or grip need be different, and a bullpup has no need for buttstock support structure jutting out the back. Pistons can add some weight, but those too are usually heavier than they need to be. I suspect the main reason is pup designs tend to use more steel than AR15s (the only comparison ever made when talking about weight, since the AR action is exceptionally light)

  • ostiariusalpha

    Nate, you got me to thinking about these heat flux issues when you proposed the idea to me of a sort of modified .22 Nosler with higher velocities from short barrels. As far as I’ve been able to imagine ways to take some of the edge off of throat erosion, I came up with 3 methods that add some manufacturing expense, but should increase barrel life.
    1. Use a composite barrel with a more durable barrel lining material. Not necessarily Stellite 25 or a Tantalum-Tungsten alloy, even something less costly like H19 tool steel would improve erosion resistance.
    2. Use a gain-twist rifling. Having a much reduced rifling twist at the leade has been shown to reduce peak pressure, and its consequent erosion, without velocity loss.
    3. Use a propellant with more advanced grain geometries, such as the Rheinmetall-Nitrochemie C4 ball powder. Getting better burn progressivity allows for lower peak pressure at matching (or even improved) velocities over conventional single-perforation geometries.
    These all work with traditional brass case designs, without resorting to using a sabot.

    • Johannes von’ Strauch

      C4 powder is rather unstable… ,and have fun to hammer forge gain twist barrels.

      There are solutions, but these arent the right ones. But dont worry, it is worked on.

      • ostiariusalpha

        The C4 powder development is a straightforward chemical engineering problem, they’ll get it worked out; these new grain geometries are the future of firearms’ propellant.

        • Johannes von’ Strauch

          New geometries are the future ofcourse, not these tough….

        • Raptor Fred

          Are you talking about Extruded Impregnated (EI) ? Like in Reloder 17.

        • Johannes von’ Strauch

          The problem is how to remove the mandrel after hammering, its not an even twist, therefore stuck.

          I worked a lot with gain twist barrels. And now are at a technology point where i dont even have need for them anymore.

      • VieteranGunsmith

        In what way is C4 unstable? It was developed because it is stable. You can shoot it, burn it, mold and shape it, hammer it and nothing will happen. It will not detonate without an initiator of sufficient intensity – period. That was the entire reason for it in the first place, to be a very stable and tolerant explosive compound that can serve in may situations. Please explain how it is possible for such an explosive compound to become unstable when used as a propellant in a cartridge.

        • ostiariusalpha

          This isn’t the RDX formulated plastic explosive C-4 that we are discussing, we are referring to a new nitrocellulose propellant design, Cubic 4-perforation. The names can be confusing though.

    • Vitor Roma

      Variable twist is such a good idea without any downfalls (except cost) that i find weird that is not common.

    • FYI, the heat flux math I relayed in that earlier post has some issues, especially when different barrel lengths are concerned.

      I need to write a new article explaining my mistake, actually.

    • therealgreenplease

      I’m just throwing this out there for someone who might know: why not hammer forge the barrel without rifling and then electro-machine the rifling?

      • ostiariusalpha

        See, that’s a perfectly reasonable solution.

        • Johannes von’ Strauch

          No it simply isnt… forging gives the steel the structure for long mechanical barrel life. While any cutting and etching destroys exactly that.

          • ostiariusalpha

            Cutting the rifling like that would “destroy” nothing. The Stellite 25 barrels made over the decades suffered no discernible ill effect from whether the barrel was cut-rifled or hammer forged.

          • Amplified Heat

            The work hardening of hammer forging is about mushing the crystal grains so they elongate radially about the bore. Cutting into the surface for rifling would do little to interrupt this.

            Even more than gain twist, I suspect that a tapered bore would pay big dividends for throat erosion as well as overall efficiency. We just need a squeezable projectile won’t foul up the bore instantly (certain polymer coatings show promise)

  • Justin

    That was a whole lot of typing and charts for something that will never happen in the U.S. Military. You bullpup people are the same as the 10mm people. No matter how much you talk about it, it will never be popular anywhere other than on the internet and with a small group of people who just HAVE to be different than everyone else. So that they can tell you how cool and different they are.

    • Major Tom

      There have been bullpups in US military service, albeit briefly. Go lookup the “M1946 Sieg Automatic rifle”.

      • Justin

        It’s 2017

        • No one

          IT’S “THE CURRENT YEAR” GUYS!

          Thank you again for you amazing insight detective.

          • Justin

            You’re very welcome.

          • No one

            Also, I may aswell ask, why did you reply twice to this? was it hard to remember the second sentence in your all of 2 second reply? or are you trying to save face?

            You seem pretty marinated either way.

          • Justin

            Because I felt like it and I don’t really care if it bothers you. I’m not worried about saving face with a bunch of anonymous goobers on the internet, lol. Don’t worry. It’ll all be ok

          • No one

            And yet here you trying to save face after making yourself look stupid only to make yourself look worse.

            You don’t really think anything through do you?

          • Justin

            You sure are a sensitive bunch of little women. Jesus.

          • No one

            So, you’re the one who started PMSing and going on some nonsensical because someone made a “pro bullpup” article (which, if you’ve actually read it, isn’t actually pro bullpup, and It’s from one of the strongest critics of military bullpups who writes here, but reading is hard I forgot.) and we’re the ones freaking out because you can’t handle being jabbed with a few passive aggressive blows?

            Lol ok buddy.

          • Justin

            Oh no! Don’t hurt my feelings! How will I ever manage to go on with my life?!!

          • No one

            I don’t know, apparently since you keep coming back to take more abuse and pretend that you’re not salty (when It’s blatantly obvious you are), Well, I can’t answer all the underlying massive issues in your life.

        • Major Tom

          And? We still use bolt action rifles and pump shotguns and yet this is not 1917.

      • noob

        Thanks for putting me onto the sieg rifle and the even more interesting Sieg adjustable compensator.

        I’d be keen to know if a replica made from his patent could be affordable today.

        Sieg obtained a patent for his compensator in 1948, as USPTO 2451514.

        • VieteranGunsmith

          That was one fugly weapon… Planet of the apes ugly. Perhaps it’s biggest effect was scaring the ginger snaps out of anyone who ended up staring down the business end… “I can’t believe you are going to unload that ugly thing at me!!! Okay, I give up.”

      • The Sieg was a prototype only, never accepted for service.

    • Physic

      Hes not a bullpup guy, he just wrote an article with basic facts…

      And dont be so sure, it wont be a stoneage bottleneck bullpup, sure. But CT changes everything.

      • I am no so sure CT plays well with bullpups, actually.

        • ostiariusalpha

          Taking the CT carbine and reversing it so it ejects like a KelTec RDB would be a cinch.

          • But then you’re dumping cases at your feet. I own an RDB, and man it’s soured me a little on downward eject. Especially with metallic cases, but I don’t think plastic would be much better.

          • ostiariusalpha

            I prefer forward eject, myself. I’ve fiddled with a feed mechanism that would work with the CT cartridges.

          • MSG1000

            What about the P90? Does it have the same problem?

          • Not as bad, because the heat capacity of the brass is much lower than 5.56mm. Shooting the RDB prone is subjecting yourself to a bunch of very hot 5.56mm brass landing right near your elbows and forearms and chest. It’s not very pleasant.

          • MSG1000

            Dang, would some kind of deflector work to throw the rounds forward? Won’t help while prone but while standing or crouching it might just be the ticket.

          • A deflector wouldn’t really help. The magazine is in the way.

          • MSG1000

            Sorry, I was referring to the P90 with that statement. Seems like a top fed shouldn’t have a problem with blocking it. Whether a deflector helps or not is the question.

          • Amplified Heat

            Or some kind of pouch, I’m sure no one has ever thought of this before. I bet it’d be useful to keep brass off the floor of tanks and zeppelins, too!

          • Giolli Joker

            Try shooting while wearing shoes… and pants. 😛

          • ostiariusalpha

            And underwear.

          • Major Tom

            And shoot standing up.

          • “Hi Fort Benning, I have a wonderful proposal for you! Here I have a rifle, it uses ammunition that meets your requirements, but at 5-8% less mass and recoil! The tradeoff is that it’s 2/3rds of a pound heavier and you can’t shoot it prone. So what do you think?”

          • Jeff

            It’s been a few weeks and I still have the scar inside my elbow from my RDB. That said, the Soldier next to me during M16 qualification got it way worse when he somehow got brass between his eye pro and his Kevlar.

          • Amplified Heat

            Were he German years ago, he’d have fluted G3 brass sticking out of his forehead spurting blood like a spitting fountain cherub.

          • Amplified Heat

            Uh, case catcher? Sheesh.

          • You want soldiers to be attaching a case catcher every time they go prone and taking it off and dumping it every time they stand up just so that you can justify issuing them a bullpup?

          • Amplified Heat

            I think an integrated catcher & magazine box would be a good solution. Either dump the catcher when the mag is removed automatically (my preferred concept), or keep them together (obvious weight/bulk penalty that may or may not be worth keeping the brass collected)

          • Alright, well you get to work prototyping that, I guess.

        • DW

          You what? LSAT carbine is a bullpup that doesn’t look like one.

    • Hahah, now I’m a “bullpup guy”, oh man.

      • Justin

        By bullpup people I am referring to people who talk about bullpups. It’s very confusing, I know.

        • No one

          Yeah, it’s like that “actually reading articles” or “looking up an author’s past writings on a site by clicking his name” or something level of hard and confusing that you have down so well.

          …..Wait.

          • Justin

            Don’t worry, it’ll be ok. Do you need me to make you a bottle?

          • Don Ward

            So this is what projection looks like. Good to know.

          • No one

            You have some really serious projection issues captain salt lord.

            Kind of like your reading comprehension issues. (Oh, who am I kidding? You’d have to at least attempt to read to fail at it first.)

        • ostiariusalpha

          But… you’re talking about bullpups. What does that make you?

          • Justin

            Like I said, it’s very confusing

      • Don Ward

        I’m waiting for you to be accused of being a lever action guy.

        Any day now.

        Any.

        Day.

        Now.

    • No one

      “Nathanial F”

      “Pro Bullpup”

      HAHAHAHAHAHA.

      Get out.

      • Justin

        No

        • No one

          YOU’RE NOT MY REAL DAD!

          -Justin

          • VieteranGunsmith

            Are you certain? We all only know what we are told…

  • yodamiles

    If we gonna load it with 108 gr. bullet, wouldn’t 6mm be better than 6.5mm? Berger 6mm 105 gr VLD has crazy ballistic. To me, 6.5mm makes a lot of sense if we going to run 115 gr or heavier load.

    • Vitor Roma

      A 108gr 6mm is very, very long, requiring a large case to propel it properly. We could have a 108gr 5.56mm by youe line of thought. A 108gr 6.5 already has a decent enough bc.

    • Physic

      Youre comparing a Steel-Copper projectile to a soft leadcore…… thats unrealistic

      With the right configuration 6mm can be made better, yes. But not with youre weights.

    • Sticky-eye Rivers

      6.5×55 in large game loads never go below 160gr, just sayin’

      • iksnilol

        That’s bull, in Norway we use 120 and 140 grain to fell moose.

        • Sticky-eye Rivers

          Which is considered inhumane in Sweden. Not saying it can’t be done, just that we do everything better than you 😉

          • iksnilol

            No, you’re Norway Lite… get over it, you suck.

  • Uniform223

    The bait has been clicked

  • Kivaari

    Last Thursday General Scales and others testified before congress about the need for a new 7.62mm battle rifle. All based upon penetration of body armor and I believe Scales financial gain should HK win the contract.

    • Uniform223

      The man is stuck in the past and knows nothing about modern tactics and small arms. It is a shame the current CoS of the US Army (Gen Miley) is (seemingly) being suckered by that man. The comments about it over at military.com and kitup are a real knee slapper. It’s an echo chamber of thought that refused to either properly research or move beyond 1965.

      • Kivaari

        I agree. Scales arguments have been weak. He’s still stuck on the Vietnam era M16 failures. He doesn’t understand that the new rifles work.

        • AC97

          Come to think of it, if you’re stuck on the failures of those era, you certainly don’t have a good idea of what the main causes of M16 failures for that era actually were (cutting costs, dirty powder, etc), or that they were in fact fixed a long time ago, not recently (or in his case, at all).

        • VieteranGunsmith

          I agree with you. General Scales’ value to Congress in this area is pretty limited, and his ideas about battlefield use of weapons are definitely outmoded and probably have no experiential basis. But then, Congress is full of people who don’t know one end of an RPG from the other, so the value of their analysis and opinions seem to be more centered around monetary gain rather than what will serve us in future battlefield situations. I have the utmost respect for any General rank holder regardless of the service, but these men are not war fighters, they are administrators. Most of the strategies used in battle are devised at the under General rank officers. Outside the military this is not well known but is none the less truthful. Asking these men to decide what a fighting force needs to do their job is a misplaced question. To a man, anyone holding the rank at that level has not had any relevant experience in battle in so long that what they do know is tainted with opinion more than based in practice.
          This kind of reliance on Generals to make decisions at the level of small unit operations and arms is the kind of thing that had the British marching directly into maxim gun fire of the Germans in World War One. It took them quite a few massive casualty producing frontal assaults on the German line to finally decide that was foolish and a waste of young soldiers lives on the battlefield – and the Generals at first blamed the young soldiers for not being brave enough or for not fighting hard enough. Someone finally got a lick of sense and decided this was not the best way to fight on a modern battlefield. The losses preceding that revelation were astounding and for the most part fueled by the egos of those in command at the highest levels. The British and French needlessly sacrificed almost an entire generation of their troops because the Generals and Field Marshals demanded obedience to their orders despite the obvious carnage.
          We need to reevaluate the “experts” and take a sober view of this matter, not simply going with what the Generals say they want in a weapons system that most of their use experience is decades old, limited to firing ranges and laden with propaganda meant to promote an agenda rather than make a decision that so many lives are reliant upon for their very survival.

    • Jason Culligan

      If anything, WW2 and the rapid advances of tank armour already answered this for us. The answer to the ever increasing armour of tanks was smarter munitions, not bigger ones. Nowadays sub-calibre and explosive munitions are standard issue for dealing with modern vehicle armour as otherwise you’d need comically large guns with conventional rounds to do the job.

      In the same light it could very well be possible to penetrate a piece of body armour at 300m with a 7.62 NATO round but the M855A1 with its composite layout can do the same for less weight and recoil.

  • Uniform223

    We should all wait to see Desert Tech come out with their MDR…

    LoL! I couldn’t keep a straight face as I typed the out 😀

    • CJS

      Don’t worry, it’ll be in the shops last month or the month before… Wait that doesn’t sound right 😀

  • Amplified Heat

    Article hasn’t even touched on weapon mass, yet. That shorter cartridge length means the action reciprocation inside the receiver and mags can be two times shorter. Without a buttstock cantilevered off the end, there is less mass needed for its support structure, while a free float handguard is basically identical between the two formats. The shorter receiver & stock are a significant weight & bulk savings, alone.

    • Whoah there buddy, hold on. The bullpup round is only a hundred and fifteen thou shorter.

      • Amplified Heat

        So mags are 1/8″ shorter, receiver 1/4″ shorter, mag carriers 1/8″ shorter, charging handle travel 1/4″ shorter… it’s not as huge a game changer as 30-06 to 308, but it’s the same type of benefit. Also the fact that a longer barrel gas system with shorter stroke is generally more well behaved all around (especially in the piston realm best suited to bullpups, though a DI RDB is plausible because of its gas handling.) Shorter BCG travel stores less energy, which means less gas force needs to be siphoned (resulting in less added recoil via reciprocating parts)

        The wider case head of the SBR round ideally requires wider mags and magwell also, as learned painfully by Grendel which will have no STANAG polymer magazines unless tech improves significantly. That impact could well be significant for chest harness layered carriers.

        The SBR round also has higher bolt thrust because of that width (see Grendel) even if the pressure is constant or somewhat less due to powder column efficiency (see WSSMs) so either the SBR will need to be stronger/heavier at the breech, or special/costly measures taken.

        Longer barrel also means milder pressures at the muzzle with more complete combustion, which may result in lighter and smaller silencers for similar decibel reductions or resultants. Definitely makes for smaller muzzle brake requirements to achieve similar recoil & pitch values.

        5″ of barrel is significant, but so is everything else if talking about all the follow-on impacts to a fully optimized equipment package.

    • ARCNA442

      You missed the part where the bullpup has 3.5 – 5.5″ of extra barrel weight cutting into its small weight advantage. If you want to be extra nitpickey, the bullpup will also have a more complex fire control group and magazine release which will add more weight.

      • Amplified Heat

        RDBs mag release is pretty simple & light, as is the P90s. Yes, the Tavor’s is a bit elaborate with the linkages. The trigger bar is more complex, but very light compared to the gas pistons bullpups seem to require vs the lightweight AR.

  • JSmath

    You could compare a 14.5″ bullpup to a 9.5″ conventional, too.

    • noob

      And for giggles I’d like to see a ballistics by the inch style graph that takes the GPC-Conventional round that has the most powder and run it through a 20 inch test barrel. Would all that fast powder take you to 3000feet per second or would the chamber pressure rip out the case head?

    • noob

      I wonder could a live fire ballistics by the inch type velocity test be conducted by reaming out a chamber on a barrel blank and loading in the powder and projectile without brass for the test?

      • JSmath

        Brass plays too critical a role in the process to be neglected, imo. The behavior of just chamber, powder, bullet would be drastically student than with brass, since the brass takes up volume, shapes and blast, helps seal the chamber, and absorbs and takes a great deal of heat with it. Even if you shaped a chamber to resemble the case, you’d get a smidge of blowby and build up residue that’d normally get ejected.

        As far as pressure affecting the casing, I feel that’s the realm and responsibility of tuning the cycling system. 18/20″ barrel info would be helpful for all the proposed cartridges, there would be an inevitable push to pair an LMG with whichever is chosen, which I imagine is what you were getting at? 🙂

  • Raptor Fred

    That was interesting. Thanks.

  • Vincent

    My dad probably would’ve been happy with a short bullpup over an m16 back in the 80’s that’s for sure.
    Though he was a world away in Korea and Okinawa, so I guess that would be a moot point.

    Anyway, I read Anthony Williams’ document on a general purpose cartride a while back and he brough up a design of his own that eliminated the neck. Seemed pretty neat, what did you think about it?

  • Joshua

    Won’t matter.

    To many higher ups are pushing for a 7.62×51 battle rifle.

    The next general issue rifle will be a battle rifle.

    • No one

      Honestly, no one (name pun incoming!) really cares what Scales thinks.

      It won’t happen.

      • Joshua

        It’s not Scales I’m talking about.

        It’s the current Chief of Staff for the Army. The top dog for the Army is the one pushing for it.

        • Interested

          Could you give me more info about that?

          • Joshua

            Chief of Staff Gen. Mark Milley is saying we need to replace the M4 and 5.56 with a new 7.62 battle rifle so that we can be able to hold our own against near peer nations like Russia, and North Korea.

            He believes the M4 will lead to innumerable deaths against nations like Russia, and by going to a 7.62 battle rifle we will be able to out range them in ways that they will take a 10:1 casualty rate in small arms compared to what we would take.

          • No one

            He’s incredibly out of touch if he thinks Small Arms are what win wars or cause the brunt of casualties then. (When it’s been the 3 A’s of Artillery, Air power, and Armor support since WW1), that 7.62x51mm will lead to some significant overmatch potential in rifles. (Aside from the fact infantry aren’t even trained to engage at the maximum range of either 5.56x45mm or 7.62x51mm rifles and carbines and the effective range difference, if any arguably with modern loadings in use is massively overblown, overmatch in Afghanistan happened with tripod mounted MMGs mounted on higher ground, which is going to just murder a rifleman squad no matter what they’re armed with.) or that he thinks North Korea is actually a peer nation. (Honestly, their biggest danger isn’t to us, It’s to the fact that they could inflict plenty of damage to populated areas in the South in a very short amount of time even with outdated weapons.)

          • Joshua

            What’s should be most concerning, is people like him are the decision makers.

          • Uniform223

            Gen Miley seems like a very down to earth type of officer. His intentions are indeed good but the execution is not, the out come however is somewhat debatable. It is unfortunate that people think/believe that out forces out outgunned. If his fear that our current m855a1 could not defeat the most current type of body armor then he should order the Army to roll out dedicated AP round in 5.56×45 (m955).

          • LVL4

            M855A1 EPR actually is the best current round against armored opponents, instant devastating fragmentation in arms/legs/neck. Something that ap projectile just does NOT do.
            And it has light recoil and more mag capacity.

            And no usual round even in AP goes trough standart military lvl4 anyways. Even 7.62x63AP.

          • Uniform223

            The m855a1 is a very very very exceptional general purpose round. It is very effective against soft targets, common barriers/obstructions, and some body armor. However it is NOT an armor piercing round like the m995 black tip. Against unprotected soft targets, I am guessing the m995 would just “ice pick”. However I would make another guess that a soft body behind armor would be a different story.

            Gen Miley is concerned about the effectiveness of the m855a1 against body armor that is comparable to ESAPI plates used in Interceptor BA and IOTV BA. These body armor types are able to withstand and defeat rounds up to 7.62x54R.

          • James Kachman

            7.62x54R ball isn’t known for its armor penetrating ability, there are certain armor types that are rated to stop M80 Ball but *certainly* not M193 or M855. Is there any actual substantive data showing M855A1 failing to penetrate vests that a slower, larger bullet would succeed against?

            If we’re hoping to penetrate body armor, methinks a 55gr high velocity AP round might be the better option.

          • Joshua

            You know what they say about the road to hell.

          • Uniform223

            Paved by good intentions

          • VieteranGunsmith

            Absolutely correct! Why bother with the weapon when it is the projectile/cartridge that delivers the pain? There is much to be said for bullets and designing them to be more effective. Standard ball ammo is simply not going to be effective against most armored troops and their vehicles. The individual rifle was not ever intended to defeat vehicular armor, but body armor is a different story. If they are really serious about terminal effects, they should be looking into the research and design/development of projectiles. That is where the difference lies, not in the weapon that delivers them. The main reason the AR platform has been around more than 50 years is because it works and it is almost idiot proof. The lower group is about as reliable as an anvil and only in extreme circumstances and severe abuse have I ever seen one fail. The AR action will be with us for many decades, like the M2 and the 1911 – they may be replaced in the weapons inventory, but they will still be a viable option for generations to come.

          • Uniform223

            I doubt NK can push out quality high end body armor similar or equal to what the US has. Russia on the other hand is questionable in my opinion.

          • Joshua

            According to Milley the countries that can make them, are selling them online to our enemies for $250 a plate.

          • VieteranGunsmith

            Russia’s problems in their economy will restrict production of such armor because of the cost per man to issue their troops would be very high, and they aren’t really concerned that much about the welfare of their troops – they were having a hard time keeping them in beans a few years ago. I don’t view Russia as a serious threat to the US, and they have not been in conflict against any opponent that rivals them in strength for a long, long time.
            We have a news media that whips up the Russians into some kind of super villains and invincible in combat, but they have never faced the US Military might, and I hope it never happens. If it does, they will find out we are more than able to thwart them in a one on one situation. They have one, maybe two aircraft carriers, their air force is basically targets for ours, they are weak in many critical areas where we outgun them in serious combat power. That is why they don’t come out and fight despite their tough talk. They know the truth of the matter and they are not stupid. We beat them in the cold war and they really don’t want to tangle with us because they know they have no hope of winning.
            Putin and his government are a lot of things but stupid is not one of them. They leave that to North Korea and Iran.

          • VieteranGunsmith

            Milley is a dinosaur. That is the same thing that went on in my day with the top brass – who incidentally never face hostile fire and don’t have to carry the rifle they want to force into the hands of the soldiers they lead. When the M16 was accepted, the first thing they did was complain about the lack of effectiveness of the round. Of course, in the theater of Vietnam, 7.62 NATO (M14) proved to be very much of a handicap for the average soldier in the field for several reasons – first it was long and heavy, second the recoil too much on auto fire, an the list of deficiencies goes on. The M14 was a great rifle but Vietnam was the wrong war for it. It was replaced for that and other reasons and some die hards just won’t let go of that. Milley and Scales are both in that category. They never liked the cartridge or the weapon because of their ingrained prejudices toward the 7.62 NATO caliber weapons. They also loved the M-60 which by many accounts could be depended on to fail at just the wrong time. The M-14 and M-60 still have a place on the battlefield, but better more modern weapons have come along and are in the process of replacing the older ones, but the round keeps on persisting.
            WHY? Because of the military logistics organization. These people are the reason many outmoded weapons live beyond their useful lives – they don’t like change, and when it comes their natural reaction is to change back to what worked two or three wars ago.
            I have personally seen the effects of the 5.56 NATO round fired from a standard service rifle on the human body, and folks, I can tell you for all these complaints about it being ineffective, that is so much bovine manure. The projectile in soft tissue cavitates much more than it’s dimensions, and if it hits bone you get this internal ricochet effect where the bullet just destroys what ever is in the path. At reasonable distances it does severe damage and blood loss, which is why the Russian 5.45 round was created – they saw the receiving end of the M16 on the battlefield and that caused them to rethink their main battle cartridge. The results matter, not the preferences of so called military experts, (Milley and Scales to be precise).
            Every war is fought with the prior war’s weapons, ammo, and often tactics and this has been the history of humankind for centuries. That is because we cannot know the future or who or where we will be fighting, but the one thing that never changes is the indomitable will of the American fighting forces to win and to bring the most firepower to bear on the enemy as soon as is humanly possible. No foe, no matter what the conflict has ever militarily beaten the United States on the field of battle, and that is a fact that the revisionists would like to do away with. Unfortunately for them it will not go away.
            The same is true of the debate on service rifles in the hands of our troops. There is always a better mousetrap, but supplying it in sufficient numbers and keeping it supplied with adequate ammo and maintenance is the limiting factor, and it will always be that way no matter what the platform.

    • crackedlenses

      Oh this is going to go well….

  • Edeco

    I used to be good at mathematical optimization. Chose not to make a career of it, sort of absorbed it into my decision making process. Now I run on pure intuition at all times 😀

  • Great article.

    It would be interesting to see what the difference is at the more extreme end of the spectrum, such as the Army / LSAT goal of a 123gr @ 3,000fps.

    • U

      (Which is a ridiculous configuration). Might be hard to calculate, its polymer and a diffrent case construction, this calculater already has some problems, so this might be quite specific.

  • forrest1985

    No. Most armies use standard layouts and others that don’t are looking at moving away from bullpups. France has, china ARE looking despite comments i have had to contary. The UKSF have fundamentally rejected the L85 and most squaddies who have used the C8 prefer it. Israel, China, Australia, Belgium and Austria seem to be the exception, although Israeli SF and Aussie SAS both use M4/AR’s. Special Ops from around the globe get their pick of best equipment and yet countries like UK, US, Russia, Israel, Canada, Poland, Germany, Australia and many many more use conventional layouts. The UK, Russia and US are probably considered the best in the world so surely they would have tested any all and bullpup designs?

    • Physic

      Bottleneck bullpups have large drawbacks, and little change for adoption. CT bullpups dont have them (such as ejeection) and large further advantages, it changes the entire topic.

      • forrest1985

        But lighter ammo will reduce weight for standard layouts too. The bullpup has definite advantages in CQB/FIBUA but I always found it difficult reloading versus traditional layout designs that felt, more natural.

        • Physic

          Depends 99,99% on training. And you can use a slightly larger flared magwell for making reloads much more easy.

          And im not talking about weight, rather ejection diffrence.

          • aka_mythos

            The bullpups suffer as a matter of conventions. It would be like trying to sell a car in the US with the driver seat on the right side… it works, there is nothing wrong with it, it’s just different and people are stuck in their ways.

          • forrest1985

            Okay that point works for US but not SF from Australia, Israel, France, and UK. All four train on bullpups before applying for SF selection and if successful, then the bullpup is gone the first chance they get!

    • No one

      China’s not just “looking”, They’ve already selected a rifle to replace the QBZ95 and QBZ03 series (that possibly has a SAW/LSW variant like the QBZ95 with the accompanying QJB95 series) that’s current in troop trials as we speak. no bullpup designs were considered so It’s basically confirmed they’re ditching.

      There’s some cancelled project photos from earlier designs that were posted here, but the actual rifle selected is different and unfortunately actual photos are still classified so no one has any idea what it actually looks like or what the specs are.

      • forrest1985

        Cheers for that info. Its along the lines of what I had heard but even further along!

    • aka_mythos

      I think the move away from bullpup s has more to do with the lack of development money spent to evolve the designs combined with a desire to have commonality of training and parts with allies. Most of the nations previously using bullpups, those weapons were developed with state funding to prop up their own arms industry. Since then fewer have continued putting money into this kind of small arms development. Steyr still has healthy export contracts and licensing agreements. FN has there bullpup and it has been bought by a few countries. The M16 has evolved through how many different variants now? -4 or 5 not counting commercial efforts. Meanwhile the resources of these bullpup manufacturers has been so limited they’re lucky to have made any variants. 5 gen M16 variant versus a 1st or 2nd gen bullpup…

      The British and French are key members who have chosen something in the conventions of an M16 for their new weapons. For the French it was because despite NATO ammo standards their FAMAS had to use a hardened casing or its have problems. In Afghanistan many of our allies using bullpups and other weapons ran into replacement part supply issues and have since wanted to move towards using something with part commonality with American weapons. We were offering them parts and ammunition that they couldn’t use. Now they are rectifying it.

      • Risto Kantonen

        Your comment already refutes your starting premise, which is: “I think the move away from bullpup s has more to do with the lack of
        development money spent to evolve the designs combined with a desire to
        have commonality of training and parts with allies.”

        The second paragraph refutes this premise. The fact of the matter is, that among other things, the bulpup design is being discarded because of logistical issues. Which is precisely the point in the second paragraph of your comment.

        • aka_mythos

          I’m trying to paint a complete picture of the situation not assert it is exclusively one thing. I’m trying to contrast the nations where the bullpup paradigm has failed with those that still use it.

          Many of the logistical issues come from the need to replace those rifles due to age, which is also why they are short on parts. The countries that did continue investment creating modern bullpups or modern variants, the adopters of those rifles did not see those logistical problems. By being so firmly embedded in the use of a domestically produced weapon and the failure to continue to reinvest has created a situation where they are forced to accept a modern weapon not in the lineage of their legacy weapons. It is a failure of capitalization and not necessarily virtues of bullpups, in these instances.

          • forrest1985

            But looking at your second argument the UK, Israel and Australia mute that point. These countries use and embrace the logistics of bullpups. Yet the SF for all countries have rejected the bullpup in favour of an AR. The UK has not long ago spent more money on upgrading and procuring more C8’s for the SF rather than usher them towards the existing supply chain and the countries standard bullpup.There is no shortage of parts or being forced to adopt a non-bullpup weapon, well except the pressure from the SF themselves.

          • aka_mythos

            The world is moving away from bullpups but the reason for that move has more to do with geopolitics and perception than the capabilities of the weapon. I think a lot of that is orthodoxy and proliferation of American SF training and schools of thought and not necessarily the technical advantages of one style of weapon over the other.

            On a technical level the advantages of bullpups are limited but present technical complexity. The advantages they afford are not necessities and are in many regards a luxury feature. This is why some have chosen it and others have not.

            On the other side by not having a bullpup our Army and Marines have this unsure relationship with their primary weapon having reconsidered different numbers of rifles and carbines, which to use over the other… while having to incorporate additional special weapons to compensate… ultimately this has been far more expensive. We’ve only been able to get around the momentary deficiencies of whatever was chosen by throwing money at it.

  • aka_mythos

    Bullpup with a 14.5″ barrel… that’s where the fun is at.

  • Audie Bakerson

    If they’re making ammo purpose made for a bullpup, they should make it electronically primed to fix the trigger issues.

    • Ern

      God please no. There are much simpler ways to do all that.

    • Kivaari

      NO. No battery dependent guns ever.

      • Amplified Heat

        Just sights, because as long as you can shoot, you can feel better 😉

    • Amplified Heat

      …or just specify you want a decent trigger in the RFP as opposed to a two-stage selector-trigger abortion. Most folks don’t even know what makes a trigger good or bad, they just know Giessele doesn’t make a drop-in for the P90. FWIW, the 3-burst AR trigger was pretty awful as well, for the same reasons.

  • jono102

    The requirement drives the design/configuration not the other way around. Whether its bullpup or conventional is largely irrelevant.
    How a military or service requirement weighs accuracy, energy, weight and portability/flexibility will decide configuration (bullpup vs conventional) barrel length, etc.

  • tsh77769

    Another way of looking at it might be that having a longer barrel afforded by the bullpup allows us to get better performance (compared to a SBR type carbine) out of an existing round. Therefore allowing a longer service life of current ammo and mags.

    • Physic

      There is no reason to adopt a new weapon and keep old ammo right now. The only reason for the us to adopt a new weapon, is by adopting new non bottleneck ammo.

      • Amplified Heat

        Right? I love the claims we couldn’t handle another service round, as though modern computer systems are as capable as they were in WWII (when we had even more service rounds than we do today)

  • Risto Kantonen

    If a new round is to be designed, is it worth it to accept a longer-barreled bullpup, or are the differences not great enough to justify the concept?

    No, the benefits are far too small and the logistical downsides are far too numerous and have a far too large impact. NATO members and their partners are looking to increase compatibility and reduce complexity, and the idea of a bullpup rifle would go firmly against that.

  • Bradley

    Your premise assumes a priority to have a longer barrel in the same size package. It makes more sense to me to have a smaller package with the same barrel length.

    • Physic

      Ofcourse but that means just its more handy, everyone knows that, no need to write about that, it would be one sentence. This article is about mathematical numbers, and how cartridges react to diffrent barrel lenghts, which is something quite a lot of people dont know.

  • John Steiner

    Interesting article. Thanks. I don’t know if it’s been discussed before, but, has there been any thought on the further development of caseless amunition? That would be a significant reduction in ammo weight.

    • Physic

      Telescoped polymer cased ammo already is light enough. Seals heat better than brass and MUCH better than caseless from the chamber. Therefore heatens the chamber much less, needs less propellant, has less recoil. And ofcourse is more envoirment and handling resistant.

      • forrest1985

        So surely an AR derivative using CT ammo with a suppressor is a good way to go then?

  • therealgreenplease

    Question: did you also account for the differences in weapon weight resulting from different length barrels? The difference between a 14.5″ barrel and a 20″ barrel are not inconsequential (I believe about 10 oz or 283grams). So for a platoon that’s about 11.5kg. Thus the weights would stack up:
    20″ bullpup ~367kg
    16″ conventional ~381kg
    14.5″ conventional 386kg
    So that’s more like a 5% weight penalty for going with a 14.5″ conventional rifle vs a 20″ bullpup. I’m a big bullpup advocate but, looking at it this way, it’s hard to justify. The only thing I’d add to this conversation is that suppressors *should* be standard on future infantry weapons so an argument could be made in favor of the balance of a bullpup.

    • Heatflux in not integrated in the article. The 20inch barrel has much more bore surface area, and uses less powder. That increases barrel life a lot, and thats absolute key for the military.

      • therealgreenplease

        That’s a really good point too though if you look at the maintenance logs from Machine Guns: Vegas you’ll see that they run into issues with throat erosion long before they run into issues with the rifling. Barrel length doesn’t do anything for throat erosion.

        • ostiariusalpha

          If you have two barrels that shoot the exact same cartridge, then no, barrel length makes no real difference in throat erosion. The improvement is based on a difference of the cartridge itself. If you require that the projectile go ????ft/s (and this is almost always the case in military firearm development), that will mean that the weapon with the longer barrel will be able to get to the requisite velocity using a cartridge operating at a lower peak pressure. This is what makes the barrel life different.

  • LazyReader

    Bullpups suck
    best exemplified by the fact that the special forces community largely eschews them (even armies with whom bullpups are standard) in favor of specialized AR derivatives.
    Britain will ditch the SA80 with most likely an AR derivative.
    New Zealand abandoned the F88 for an AR derivative by Lewis Machine and Tool
    France has ditched the FAMAS for an AR derivative, the HK416
    Even Israel retains AK and AR derivatives, the Galil and MK18 because the Tavor is the worst bullpup currently in production. If you like a gun with an easy to drop magazine release, so rear heavy it’s ridiculous, poor controls, terrible ergonomics, no adjustable gas by all means get a tavor.

    • XT6Wagon

      psst, your bias is showing

      • VieteranGunsmith

        Bias with rationale is not a negative thing, it is a logical conclusion backed by evidence.

    • forrest1985

      Israel SF use M4’s and even the Aussie SF use M4’s when regular army use F88! If you watch english news and papers at the moment there are alot of armed police using AR variants. Even the new CT police we have use Sig MCX. The Army will be looking at this and asking questions soon if not already can they have an AR derivative.

    • *correction: bottleneck bullpups suck. Not CT Bullpups tough….

  • forrest1985

    UK and US SF get a great deal of selection when it comes to kit and will most likely have tested the F2000. The fact it hasn’t been accepted suggests its not a contender. In fact no bullpups have.

    • Amplified Heat

      Trained guys will tend to select familiar stuff they were trained on; who’da thunk it? This goes for req-writers & selection committees as well. Recall the incomparably successful AR was universally hated by the military system, and had to be forced into adoption by civilian leadership “that didn’t know anything about fighting”

      Those same wise Ordnance elites thought that M14 boondoggle was the solution to their problems.

      • forrest1985

        Interesting point but kinda mute. SF guys from UK, Israel & Australia must serve in regular units before passing selection and joining their new unit. Therefore they would have trained on bullpups since joining the service, yet choose an AR15 type weapon.

      • VieteranGunsmith

        Yep, I was there during that, and you are absolutely right. McNamara had to force the military die hards to accept it. In my opinion that was still the right decision. The problems with the M16 early on were self inflicted wounds – the cost cutting lack of chrome plating the bore and chamber, the use of non spec powder in the ammo, and the fallacy that because of smokeless powder the rifle did not need a cleaining kit issued, all were done to save money and both cost the lives of personnel in the field. Those were ironed out and the weapon gradually improved in reliability and accuracy through research and development. That is why 50 years later the heart of the AR system has been relatively unchanged. Every firearm ever fielded has gone through this, including the M1 Garand. The reputation for the M16 not being enough gun is a longstanding myth. I personally was issued the M16A1 and with GI ball ammo I never saw anyone get up and keep fighting after being hit center of mass with 5.56 NATO. Not once during my tour did it happen, not ever. That is so much beer hall BS. The M16 is very capable of doing the job – so much so that the USSR developed a new ammunition based on their 5.45 caliber projectile – this was because of the damage the 5.56 NATO round did to our enemies.

    • NoNamesOnTheNet
      • forrest1985

        That we know of. Also Belgium, Austria and (for now) China are only countries to my knowledge where both main force and SF use bullpups.

      • Shocking… the Belgium military uses the rifle that their national factory is promoting as their top assault rifle product, just as they have done with FN weapons and the Belgian military since, oh, forever?

        This is my shocked face.

  • Seamus Bradley

    You forgot to calculate the simple fact that Bullpups weight more that Classic rifles. Those extra 6-8inches of barrel steel, and trigger linkage don’t also come without a weight penalty. All this talk about weight being toward the shooters shoulder and not out forward ignores the simple truth that weight is weight and you still gotta hump that thing everywhere you go. I wager that the extra 1-2lbs on the bullpup design per person for a whole platoon will surpass the 68.6lbs of added weight to the platoon of a classic style rifle.

    • XT6Wagon

      You don’t need a stock on a bullpup. There is no natural reason for a bullpup to be heavier for a given level of performance. Here you are talking about the bullpup acquiring a much better level of performance by using a 16-18″ barrel instead of a 10″. I suggest anyone who would prefer the ballistic performance of 5.56 out of a 10″ vs a 16″ barrel is insane.

      The F90 version of the Aug is 7lbs, while a M16 is also 7lbs.

  • jerry young

    Given all the charts, graphs and ammo specs I’m still an old school long rifle fan, to me a bull pup rifle feels uncomfortable to shoulder and shoot plus I just don’t like the looks, Just my opinion and no egg head studies or any other means will convince me otherwise, I will probably never see close quarter fighting since I am no longer in the military out on missions and god forbid war comes to our streets that would press me back into service but if it would I’ll still take the M16 over a bull pup.

  • spiff1

    Has any one thought of the tried and true AUG? Available in 5.56 NATO and .300blackout, used by several nations over the last 30 years or so…Versital, reliable, field expedience for maintenance, quick barrel/caliber change ….And more!

  • Amplified Heat

    The comparison gets more & more extreme as size becomes prioritized as well. Look at the MP7 and P90 which I believe approached the design in a similar parameter based manner. One is a miniature G36 with tiny short barrel and achieves adequate AP performance with hard steel ammo driven to such high pressures the gun requires factory overhaul every 4000 rounds and costs about twice that much itself. The other sports a more typical subgun length barrel and operates on a simple straight blowback action with few added complications, and makes up for its more awkward mag placement with a much higher ammo capacity. Unless you’re a government that thinks it has unlimited funds, there is only one good solution, and it isn’t the ‘traditional’ layout.

    But as you go to more powerful rounds that need longer barrels, that same ~5″ savings in length becomes proportionally less significant, and the action-timing complexity benefits disappear. Oddly enough, once you get over a certain size, length again becomes critical since it makes the weapon too awkward to handle, and bullpups once more come into their own as heavy sniper or antimateriel rifles.

  • Amplified Heat

    RDB licensed copy by FNH or B&T in 6.5 Grendel, please 😉

    • XT6Wagon

      6.5 creedmoore….

      after all I don’t have to wander around Afghanistan with 120lbs of kit so the extra ammo weight doesn’t matter to me.

  • Jack Matthews

    What about a 14.5 inch barrel bullpup?

    • mig1nc

      The IDF issues the MTAR/X95 in a carbine length barrel, so it makes sense to them. Why not?

  • idahoguy101

    The millions of m4 carbines will soldier on for the 80 plus percent of POGs. Not enough reason to change that. For the actual front line rifle trigger pullers give them whatever is best for the task. Cost per unit really isn’t that important when arming trained infantry

  • jonp

    Why 6.5? Why not .243? Throat erosion? There are a great number of assumptions made in the write up but you need to do that I guess. Still, they seem arbitrary

    • Truth

      It was just an example, its just a GPC of Anthony Williams, …dont expect advanced ballistic knowledge or any actual optimisation of him.

      • jonp

        Hey, im all for discussion if things in the fireatm realm

        • Truth

          An ATM on fire? Or an ATM where you can get fire? Or and ATM in the Firenation?

          What do you want to discuss about, im open for that any day.

    • They are arbitrary. It is just an example.

      • jonp

        Oh, ok. Very interesting article. Well Done

  • snmp

    Funny, cause in moderne armies you need more mechanical engineer, Armement engineer, trucker, cooker, Mount troop in amorcar than man who do small walk …. and they need to short weapon with long barel …

  • VieteranGunsmith

    I think where the bullpup falls short is in open long range shooting. The reason I say this is basic geometry. The distance between the muzzle and the shoulder being shorter makes minor changes in hold on the target dramatically amplified compared to a conventional rifle design. This is similar in action as the sight radius is in iron sights. The longer *to a point* the distance between the shoulder and the muzzle, the more tolerant of human movement the weapon will be for point of impact at range. This is why you don’t see short sniper rifles. Every serious long range shooter relies on this dimensional relationship to help them mechanically with putting rounds on target at extreme distances.
    That, and the triggers on most bullpups are terrible which is a large factor in long range marksmanship hurt them. Even a stock GI trigger in an AR platform rifle is superior to the bullpup trigger in feel and controllability. This is why you see so many aftermarket triggers for the AR out there, the fact that the GI trigger is not the best and there are a myriad of options that are better tells you that there is room for improvement. The fact that even the worst GI trigger in an AR rifle is demonstrably better than the best bullpup trigger is a matter of mechanics. The AR trigger works because of the close and minimum number of contact areas in the parts. Bullpups all have a mechanical linkage that connects the trigger to the sear/disconnector, and in having that link there is compromised rigidity which makes them feel spongy and full of creep. The bullpup that solves that will be the one to have, but then you will still have the length issue in relation to long range accuracy.

    • XT6Wagon

      Well, you can have a perfectly good trigger in a bullpup. RDB comes with a good trigger out of the box. Never seen a single review that thought it wasn’t better than a AR-15 stock trigger. Its not built for bleeding edge accuracy, what with being about as far from free floating the barrel as possible without going the other way where its well supported like a WA2000.

  • VieteranGunsmith

    What? No aquarium bubbler on it??? Is there any accessory device that has not been hung on this thing? One thing that has been neglected in this discussion is this: If stuff goes sideways and you are overrun, do you want a bayonet a foot from your face, or would you want it to be somewhat further away? This is important because at some point someone is going to close the distance on you and you are going to want the power and reach afforded by a battle rifle versus this compact of a weapon. The only place bullpups make sense is in CQB/urban combat, room to room fighting, but that is not the only place our soldiers and marines fight the enemy. If you expect to block and parry a bayonet thrust from an AK wielding opponent, that bullpup is not going the weapon of choice, so you better have an endless supply of ammo, or you may end up on the end of the other guy’s sharp pointy thing on the end of his AK.

    • NoNamesOnTheNet

      That’s the issue in the first place, because on the flip side, a 3 foot long rifle has its disadvantages when being used in an urbanized environment. Or, a vehicle–with everyone’s brass bouncing all over the place.

      It’s about weighing likely against the unlikely.

      If anything, the argument against a bullpup would be the cost and difficultly of retraining the whole force in a new manual of arms.

  • Corey

    The projectile is too large. If we want to get a next gen cartridge it will need to be .24>_<.25 diameter to yield velocities of 3500fps or more. Solid metal projectile. Speed kills.

  • The big thing most shooters shooting a bullpup is they are usually held close the chest while the conventional arms tend to relax the dominate hand holding the rifle. It is why the p90 clipped to the vest so that the arms relax instead of being held close to the body too much tension on the muscles you tire too easy and grip the handles tighter. The firing is with the elbow way out from the body as you try to create pivot with your body. Which allows for the barrel to swing around faster but with your hands in a traditional boxing stance you can stand there for about five to ten times as long not moving and acquire a better sight picture if your not moving. If you moving the bulpup is better for tracking wasted rounds into the target. The faster you are moving when aiming the more rounds are needed to gauge the rate you need to pull the trigger to accurately hit the target. If you look at the old pop up turrents you notice the angle of the gunners grips on the butterfly triggers is the same angle the gunners hold conventional rifles or maybe a little bit looser.

    It might be simpler to focus on what is needed. One you need more than sixteen inches of distance for the bullets to straighten out, the faster the bullet the more of spiral length you need to prevent tumbling. At close range tumbling is sometimes better but more likely to deflect off body armor and even heavy clothing depending on the angle as it is not moving in a hard arc but spinning more like baseball. Most bulpups are disigned to bring the rear grip in front of the action. They are basically submachine guns that are heavier to shoot the same rounds as conventional rifles. The conventional stocks are dead space from the action to the buttplate as they set distance between the hand and shoulder that is comfortable to shoot or hold at ready for mintues at a time. Bulpups move the action closer to the face so that the barrel length is moved closer to the face. There are old wwii guns that worked that way with the guns loading from the side. Companies continue to go back to the distance of about six inches from the face for six foot tall person with shorter people closer and taller people further away from the face. Most of the old M16 had cotter pins to adjust the draw length but you don’t see those these days. I remember back in 2000 when they big thing was caseless ammo and bulpup designs, the problem is they tend to recoil at an angle into your collar bone which if you shoot ultramag you might not even notice but if you are used to the gentle push of an m-16 might throw off your aim point. Likely they end up shotgun style guns with a hip arm to brace against and only aimed when you can decent cover and time to think. But that is more an issue of not having good overwatch or having to move too much while aiming. Getting a good position ofter requires a set battle field not having to shoot the door knobs off potential sites, I know more guys spent time repairing doors on bad intel than shooting people back in 00 and 01.

  • James B.

    Conceptually, I’d like to see a lightweight rifle round that can be accurate and lethal out to 800m with a long barrel, while still being effective to at least 200-300m from a very short barrel. I expect something already exists in the 6.5-6.8mm range.

    I’d also like to see a rifle upper with a piston and the spring located forward, which could then be mated to either a conventional-layout lower or a bullpup lower. With those options, infantry weapons could vary widely, up to a conventional long-barrel rifle, down to a short-barrel bullpup PDW, but most of the working parts would still be common to all models.

  • Richard Lutz

    No, no, no. The New Zealand military replaced their AUG variant with an AR. Case closed.

  • U.S. Army: « We want a rifle that’s maneuverable in close quarters. Maybe bullpup? Except it has to be usable for left-handed and right-handed shooters too. Oh, and has to be light. Oh, and possibly explore calibers other, or more powerful, than 5.56mm… did I mention we want an Interim Battle Rifle too?»

    Industry: « Say no more.»

    https://uploads.disquscdn.com/images/cd625ff2b4d47679e241da120550f2718f9f31683c9987e829a2345d9da5a98a.png

  • KitCarson

    Australia has redefined the AUG, go with it.