History of Assault Rifles and Ammunition

Anthony G. Williams has updated and expanded his history of Assault Rifles And Their Ammunition. Tony knows more about cartridges than anyone else I know and I doubt that there are many people who have fired more types of assault rifles than he has.

Attempts to improve the power and range of the SMGs, such as the development of the .45 Remington-Thomson in the experimental Model 1923 Thompson SMG (which used a very powerful loading developing almost three times the muzzle energy of the .45 Auto) and the use of the 9×25 Mauser round in the 1930s Solothurn S1-100 and Hungarian Kiraly 39M and 43M SMGs (which saw some service), did not catch on. There is a limit to the degree to which the performance of such weapons can be increased as their large-calibre, relatively light and round-nosed bullets lose velocity quickly. Also, the basic API blowback system used by most SMGs is not suited to high-powered ammunition, although the Kiraly and Thompson M1923 had more sophisticated mechanisms.

A selection of WWII and Post-WWII Assault Rifle Cartridges

( Assault Rifles are defined as “military rifle, capable of controlled, fully-automatic fire from the shoulder, with an effective range of at least 300 metres” )

Steve Johnson

Founder and Dictator-In-Chief of TFB. A passionate gun owner, a shooting enthusiast and totally tacti-uncool. Favorite first date location: any gun range. Steve can be contacted here.


  • John Doe

    .300 AAC is the future. I would love to see the U.S. military adopt it.

    • Jay

      Why is .300AAC the future? It’s nothing more than a 7.62x39mm clone made for the AR15. It has no juice at longer ranges. It would never be used by the military for anything but specialized suppressed applications.

      • Sian

        The 125gr supersonic claims an effective range of 500 yards, which is well beyond where an M4 carbine has appreciable wounding effects. Sure it’s no 6.5 grendel, which can reach out twice as far, but it’s versatile.

      • Other Steve

        I really wouldn’t consider it the “future”, or as worthless as you describe.

        You have a little reading to do if you think 300blk is JUST 7.62×39. It’s a smaller case, more common bullet diameter meaning wider selection, a pressure specification that allows non/suppressed, super/subsonic with no changes or major increase in cyclic rate, loads and feeds to full capacity in AR mags, doesn’t have the reliability issues with 7.62×39 in the Ar platform, provides more energy than 556 or 7.62×39 out of short barrels.

        Combined, that’s something that no other round has done yet. It will not replace 556 for light carbines and it won’t replace 308 rifles, but it will likely replace short barreled carbines and subguns like the MP5.

        The fact that is suppresses far better (in super and sub) than 556 is just icing.

    • Brandon

      300 Blackout’s supersonic performance is nothing special.

      • John Doe

        It is compared to 5.56. In a short barrel application, which is more maneuverable in combat, it’s far more effective than the M4 chambered in 5.56. The U.S. military will never adopt the AK-47, so .300 AAC is the best option. They keep everything in their current arsenal and only swap the barrels.

    • W

      i cannot say if 300 black out is the future, though it definitely threatens the future of submachine guns (given AR15 SBR evolutions) and PDW cartridges. It would delight me to see this cartridge replace SMGs and PDWs, considering how effective it is in close combat and with a suppressor.

      • Chase

        This is especially true if we here in the USA become more accepting of bullpup guns.

      • JMD

        I would love to have something like a suppressed MTAR-21 in .300 BLK. That would be great.

    • JMD

      While .300 BLK is probably the answer to some of the military’s problems, I don’t think it’s the end-all solution. Beyond that, it runs into at least one major potential problem I can think of when issuing it to “average guys”: have you seen what happens when someone accidentally fires .300 BLK in a 5.56x45mm rifle? It’s a disaster, and it’s easy to do because the force of the bolt closing will ram a .300 BLK bullet into the case far enough and fast enough for the whole round to chamber. Look up the pictures from the handful of people who’ve done it in the last year if you have any doubts.

      I personally think that bringing .300 BLK into the mix on anything but a very limited scale for specialized applications by highly-trained troops in the military is not a good idea for that reason.

      • JMD

        In response to John Doe’s post…

        “.300 AAC is the future. I would love to see the U.S. military adopt it.”

  • Samopal

    Unless the definition changed when I had my back turned, Mr. Williams forgot the “chambered in an intermediate rifle cartridge” and “fed from a detachable box magazine” part.

    • SpudGun

      He definitely mentioned the intermediate cartridge in the opening few paragraphs – defining the difference between a Battle Rifle and an Assault Rifle.

      • Samopal

        Ah, I haven’t had time read his article yet, I was just going off Steve’s little summary. Thanks.

    • Chase

      “Chambered in an intermediate cartridge” is supposed to be implied by “capable of CONTROLLED automatic fire.”

  • Jay

    Anthony G. Williams knows guns like very few others.
    I have a few of his books and they are all outstanding!!
    I first found his site about nine years ago while looking for info on WW2 fighter aircraft weapons. His book “Flying guns of WW2” gave me all I wanted and then some.
    I think his books should be mandatory reading for most firearms enthusiasts. Hats off to him!

  • SpudGun

    A very informative article – though I couldn’t absorb all the information in one read – so will have to go back. Well done Tony.

    If I have one complaint about the article, it’s the writing off of the 5.56mm round in a short barrelled rifle. If the US Military goes for a 10 inch barrel, then I’m positive that there are rounds already available (with faster burning and more efficient powders) that will produce the velocity needed for yawing and fragmentation.

    Other then that, a great read.

    • Other Steve

      I’m not sure why you are so positive there is a good solution for short ARs.

      The only way to get more energy out of a short barrel (where we’re already talking modern fast powders) is to increase the bullet weight. Since 77gr MK 262 is already pushing for size in the 556, I’m not sure where you expect them to go.

      The 80gr tracer rounds aren’t designed for terminal effects, and even if you could load anything heavier you’re going to start running into OAL length issues (reliability, feeding, fit inside the magazine), not to mention a new twist that carries it’s own issues with barrel life and usable ammo range.

      A 300blk AR is going to be able to go a lot shorter with more energy than a short 556 EVER will. That, I think is the likely solution for very short rifles.

      • SpudGun

        If the loss of velocity from a 10 inch barrel is only a few hundred fps, then it is totally within in the realm of better powders / bullet design / barrel rifling to push it to the magical 2700 fps for consistent yawing and fragmentation.

        I wouldn’t be surprised if these rounds were already available to the Special Forces community.

        As for the change up to a larger caliber, that is a debate for another time. 😉

      • W

        I think a good solution for a SBR is the mk 262 round. This cartridge is far more effective than the M855 green tip.

      • Other Steve

        That doesn’t change that fact that if we’re using modern powder, a fixed OAL to fit in a fixed magazine, and a fixed barrel length in this case “short” like 10″ or so.

        The time and rpm to stabilize anything is going to have a diminishing return that the only solution will be to increase the diameter of the round. 1:7 twist is already cutting into barrel life, so 1:5 or 6 is unlikely even if it did fit in the magazine.

        Whether it’s 300blk, 6.5, 6.8, or other, it’s all going to have more energy and terminal effect than the 223 EVER will considering a fixed barrel length and a fixed OAL round length. This is pretty simple math.

        You have to increase the diameter, there really is no magic 223 bullet unless you can increase the OAL, which you can not. There would have to be a substantial development in powder, and even then you’re going to be pressured over the strength of the receiver so… again…. DIAMETER.

    • JMD

      A big piece of the issue here is the 5.56x45mm case’s small powder capacity. You could get a lot more energy behind X weight of .224″ bullet by loading that bullet into a fatter case. Look at .22PPC for instance.

      The 5.56x45mm has been made to accomplish great things, but at it’s root it was designed to push very light bullets at very high speeds from a 20″ barrel. It excels in that role. As soon as you deviate from that, you start running into problems. Anything you do with that case to increase performance is going to run into some kind of problem, whether that’s a larger diameter bullet (6x45mm or .300 BLK), or a heavier .224″ bullet (Mk 262). In the end, there’s only room for a maximum powder charge of about 25.5 grains, depending what powder you use and how much room is left after seating the bullet, and then at those maximum charges you start running up against pressure issues, which cause their own neat set of problems. Good projectile design and more efficient powders can help address some issues….

      …but… At it’s root it’s still not a short barrel cartridge, or a subsonic cartridge, or a cartridge for heavy-for-caliber bullets, etc. You can’t cheat physics.

      People need to stop trying to use the wrong tool for the job, is what I’m getting at here. There’s a right tool for every job. In the world of firearms, the tool is a system. The magazine, the ammo, the firearm’s barrel length and operating system etc., are all a part of that tool system. If you change one part, you’ll need to change something else to adjust, and some adjustments just don’t make as much sense as others.

      Stop trying to drive heavy gauge nails with a tack hammer, just because the tack hammer is what’s already in your hand.

      If you have to have a barrel less than 13″, 5.56 cannot be adjusted enough to continue to be the right tool for the job. A new cartridge is required. That’s where things like .300 BLK come in.

      If you need a 22″ barrel and plan to shoot at ranges further than 800 yards, then 5.56 is not the right tool. That’s where 6.5 Grendel comes in.

      The basic AR platform allows this kind of modularity. That’s part of why it’s growing after all this time, not fading away. Ignoring that modularity in favor of trying to ram a square peg into a round hole makes no sense.

      Stop trying to cheat physics, and just pick the right tool.

      Unfortunately, the right tool is sometimes extremely expensive and a massive logistical burden for organizations as large as those in the US military who are being told to deal with this issue.

      Fortunately for the rest of us, we each only need to supply one person (or maybe a couple in a family situation), so there’s really not much excuse to continue to pick the wrong tool.

  • charles222

    epub version available?

  • charles222

    Oh, blargh. Thought this was a book, never mind :p

  • Doesitmatter?

    Tony’s page is the benchmark, no doubt about it. I have been going there for long time. Max P’s is also very good one, but I contracted deadly software virus while perusing it – 2times already so I obstain from there; sorry I have to say it. I wonder if he can do something about it.

    • Oneirolus

      Seconded. I too have got infected at Max’s site. Its a real pity as its perhaps the best gun site on the web.

  • Vitor

    The British 7×43 must be the most underrated cartridge ever. The right amount of power with great BC.

    • W

      it was certainly ahead of its time… 🙂

  • michael

    the best out of short barrels is NOT the 300blk but the 6.8….

    c’mon people, let’s use our heads here and not interest of the moment

  • Whatever

    One thing I don’t get about the US when they adopted the 5.56 round is that they knew about the 7.62 x 39 round. Why didn’t the US military design a round that was just a wee bit better ballistically than the Soviet round? They could have used a bullet a bit smaller in diameter, like 6.8mm or 6.5mm, and pushed it a bit faster, like around 2600 fps.

    • Jay

      There was no scientific process when they went for the 5.56mm. They didn’t come to 5.56x45mm by doing research and testing multiple cartridges to come up with a solution.
      Remember what the combo was designed for? It was designed as PDW to replace the Carbine.
      Someone really high up liked it, (McNamara), and shoved it down everyone’s throat. The same with the rifle. Once the army got stuck with it, they became the slaves of the little cartridge, the little rifle and that “disposable” magazine. A vicious circle.
      You can’t make a new cartridge with enough performance and performance at range, to justify a change, since everyone wants it to fit in that small AR15, “disposable” mag.
      Everything has to be compatible with that AR15 and it’s mag. Then every time you have new rifles people say it doesn’t do enough over the AR15 to justify a change. Well, how could it? It has to shoot the same cartridge, from the same mag, to be compatible with every toy made for AR15 how could it be dramatically more powerful? On top of that, you have generals who were in charge to find solution, retiring with fat jobs at Colt and you wonder why there’s no progress? Development and testing costs big money. Why not just keep pumping out the 50 years old rifle and pocket the money for development and testing.

      Just pray LSAT gets funded, since that’s the only way you’ll ever get our of this vicious circle. ……That or if people wake up and hang a few dozens generals and politicians.

      • W

        jay, i am impressed by your post. I have lost all confidence that a replacement for the M4 will be adopted, primarily because of the attitude of “well, its good enough…stealth destroyers and joint strike fighters are more important anyways”. A revolutionary technology like LSAT or caseless technology is essential to changing the US military’s view on small arms.

        I believe that when it comes to small arms, any little advantage the US military gains by adopting a newer system is essential to our effectiveness on the battlefield. By reducing the human error factor (by fielding a more modular and less maintenance intensive rifle/machine gun), soldiers can be more focused on executing their missions.

        It is fascinating that the US military flirted with the idea of intermediate cartridges, with the .276 pederson and .256, and the british with the .280. These cartridges, which were dropped in favor of the 7.62×51 and, later, the 5.56×45, would have successors such as the 6.8 rem in the 21st century.

      • Hainabu

        That’s not true, there were scientific researches in the ’50s and the ’60 that showed the superiority of the small calibre weapon systems, look at SALVO project etc. They tested several calibres in the 6 mm calibre range as well but the 5.56 ( for you the .223) was found better for the assault rifle role.

  • Lance

    Sorry to show 5.56mm or 7.62 NATO isn’t in that pic. I do see 7×33 Kurtz which is a classic so is .30 Carbine in the front. The later one on the far right is weird looking.

    • Simon_the_Brit

      This is what calibres they all are. I nicked the list from Tony’s website, I hope you are OK with that Tony. I’ll get you a beer next time I’m at Deepdale/Bisley.

      .30 M1 Carbine, 9×35 Lahti, 9×40 Lilja, 7.92×33 Kurz, 7.62×39 AK, 7.5×45 Czech, 7.62×45 Czech, 7×36 Madsen/Otterup, 7.65×38 French,7.5×43 French CRBA, 7.62×38 Swiss, 7.92×40 CETME

  • Charlie

    A 243/6mm round would be superior to both.

  • Colin

    Back in the 60’s (us) Brits were experimenting with new calibres, the favoured one was in 6.25mm using the mk.1z case from the EM-2 necked down. It got canned for the 5.56 trials (nothing over 5.56 allowed or something). I’ve been playing with photoshop, if you take a 7.62 and resize it to 5.56 length it comes out at about 6.2. Have a look at this and tell me it doesn’t look good (and as they, if it looks good…)


  • sansenoy

    Everyone seems to be convinced the .300 BLK is a perfect subsonic round, why did the russians dump the subsonic 7,62 and make it a full 9mm then? Especially considering their habit of adopting flawed solutions and fixing them in about 15 years time…