World War II "practical" assault rifles/automatic carbines

[BarnOwlLover]

Sort of like the SHTF version of this thread, but more practical. Not ultimate "desperate times means desperate measures", but still has to take into accounts realities of World War II era production techniques and materials. Hence, minimal heavy machining is desired. Use of stampings and such will be favored, but it doesn't have to be absolutely crude. Also, no aluminum forging or extrusions (not really a thing in World War II outside of the aviation industry), no polymer (modern polymers were in the infancy at the time), but still simple methods are desired.

As far as that goes, I'd put forth some simple but not too crude rifles, like say the Sig 540, Beretta AR70 and AR70/90 and the CIS SAR 80 and SR 88 (early versions without the forged alu. lower receiver) as starting points or points of possible inspiration. As far as mechanism, something simple like a tilting bolt or more likely an AK-type two lug rotating bolt with either a long stroke or even some type of short stroke piston.

Also, like in the other thread, what would be suitable for use as a round for this type of weapon by the standards of the time?

 

[BarnOwlLover]

Now for examples thinking about this thread and what I do intend for it's scope to be. I'm going to break it up into the "most likely to be practical" given common World War II production methods or at least what would seem to be appealing. The second category would be what I call the "outlier" category. Stuff that "conceivably" may've been made in World War II if a few changes get made, mostly in terms of materials or production methods. This will be subdivided into "mild outliers" and "extreme outliers" based on production methods and perhaps even performance. For instance, something like a basic gas piston AR-15 designed for "no frills" production would be a "mild outlier" based on being made out of aluminum forgings (easy to work with if you have access to the materials and machinery), but stuff like say a HK416, FN SCAR, CZ Bren, or HK433 would be perhaps at best "extreme outliers" due to costs and production methods (all have cold hammer forged, chrome lined barrels, which that combination wouldn't become common until years later in service rifles).

Now, for a list of practical examples, I'd include stuff such as:

Beretta AR 70 and AR 70/90
Sig 540 or 550
CIS/ST Kinetics SAR 80 and SR 88/SR 88A
Imbel MD2/3
Imbel MD 97 with steel "lower" receiver
Howa Type 89
FARA 83
HK roller delayed weapons (includes CETME and Sig roller delayed weapons)
AK-inspired weapons
AR-18/180 and similar rifles (like Sterling's similar lines of rifles designed separately from the AR-180)
And other similar items.

Mild Outliers:

"Simple" gas piston AR-15 (including like the T65/86/91, or Colt Model 703)
Forged AK-type weapons
"Full" Imbel MD 97 (with the aluminum lower, why it was based on a redesign of the MD2 family of 5.56mm FN FAL rifles to use an AR-18 type rotating bolt and gas system instead of the original tilting bolt system of the FAL)
VZ58
FN CAL (with a simplified bolt)
FN FNC (simple, but used a forged aluminum lower)
And similar items.

Extreme Outliers:
HK416 (high quality, CHF/CL barrel)
HK433 (extruded aluminum upper, polymer lower, high quality, CHF/CL barrel)
FN SCAR (extruded aluminum upper, polymer lower, high quality, CHF/CL barrel)
CZ Bren 2 (forged or extruded aluminum upper, polymer lower, moderately high quality, CHF/CL barrel)
FB Radom MSBS Grot (extruded aluminum upper, polymer lower, moderate quality, CHF/CL barrel)
FB Radom Beryl family (high quality AK derivative, CHF/CL barrel)
HK G36 (probably biggest extreme outlier--mostly polymer receiver, CHF/CL barrel, but pretty inexpensive).

Now caliber. SCHV is allowed for discussion, though it didn't become a big deal until after the Korean War for US ordinance, and more so until Vietnam and after. Though World War II era, and even pre- and post-war experiments are worthy of discussion.

 

[Alan Stevens]

How about a U.S. M2 carbine with a 30-round magazine and select fire.

 

[BarnOwlLover]

Not an assault rifle by US Army/NATO definitions. .30 Carbine isn't an effective assault rifle round generally speaking to 300+ yards/meters. Not to mention that though it was more widely used than envisioned, the M1 and M2 carbines were originally envisioned as PDW-type weapons. Basically a World War II version of the HK MP7 and FN P90 (though only the Germans and Belgians currently use them in the PDW role).

 

[Alan Stevens]

Not an assault rifle by US Army/NATO definitions. .30 Carbine isn't an effective assault rifle round generally speaking to 300+ yards/meters. Not to mention that though it was more widely used than envisioned, the M1 and M2 carbines were originally envisioned as PDW-type weapons. Basically a World War II version of the HK MP7 and FN P90 (though only the Germans and Belgians currently use them in the PDW role).

Many soldiers loved them when fighting in jungles and places like Iwo Jima, where a close-in weapon was ideal for assaulting pillboxes and blockhouses. Of course they carried grenades and satchel charges as well.

 

[BarnOwlLover]

And that's basically what the M1/M2 carbine was designed for. It was not designed for assault rifle ranges (300+ yards/meters), let alone full power service rifle ranges. It was designed to basically cover a close-range gap between say pistols and SMGs, and what now would be assault rifle or the lower end of full power service rifle ranges.

Remember, the M1 carbine program started up due to issues that support troops (machine gun crewmen, logistic troops, artillerymen, vehicle drivers, etc) had with the M1 Garand and M1903 Springfield being fairly long and heavy for their full-time use. But it was felt that such troops shouldn't be armed with SMGs (limited range, and perhaps a bit overkill at times for CQB), and that a bolt action M1903 carbine had limited firepower (a semi-auto weapon at minimum was desired), and the the Colt M1911 pistol wasn't the end-all, be-all as a PDW (most pistols are hard to shoot well, have limited range and firepower, and are, even when widely issued as with the US, British/British Commonwealth, and Germany, were often held to be back up weapons most of the time).

The US Army envisioned the M1 carbine's performance maxing out at 300 yards (start of high-end assault rifle effective range, which typically runs to 300-600 yards/meters, though some troops like French troops in Mali have accurately engaged point targets with HK416s out to nearly 700 yards, but this being modern era, is sort of not here or there aside from illustrative purposes). This was what was envisioned due to the Army being aware of what German paratoopers were doing in 1940 in places like Belgium and such, and paratoopers overall often were deployed for relatively close range or even CQB combat ops.

But in overall terms, it's probably best as far a something like an apples to apples comparison, you can't really compare a M1/M2 carbine to a "true" assault rifle. Even the StG 44's 8x33mm round wasn't that great ballistically (MV of 2200 fps out of a StG 44, and like most 7.62x39mm loads has a short stubby bullet that behaves a lot like a pistol round in soft tissue. IE, not a ton of trauma or such being done beyond the actual wound track--while full power .30 class rifle rounds and even SCHV rounds tend to tumble and often fragment in soft tissue due to being tail heavy and often bullet construction meeting high velocity).

A more fair comparison wold be comparing a M1/M2 carbine firing .30 Carbine to say a lever action or even semi-auto rifle firing the .357 Magnum revolver round

Ironically and interestingly (though not during World War II obviously), Ruger has made .357 Mag and .44 Mag autoloaders that were broadly based on the M1 carbine.

 

[Alan Stevens]

Ironically and interestingly (though not during World War II obviously), Ruger has made .357 Mag and .44 Mag autoloaders that were broadly based on the M1 carbine.

The 30 Carbine round has twice the muzzle energy of the 45 ACP round

 

[GrauGeist]

If you're looking for close quarter combat and trench clearing, than the Thompson M1919 is your choice.

 

[SaparotRob]

The 30 Carbine round has twice the muzzle energy of the 45 ACP round

 

[BarnOwlLover]

Problem is that (in modern context) 5.56mm/.223 Rem (not identical, but can usually be safely and easily fired from the same rifles), especially with heavier bullets of more modern construction commonly available now, can generate energy values equal to or superior to the .30 Carbine out of a SBR vs the .30 Carbine out of a 16-18" barrel. And you can still hit things with it at longer range, again even with a SBR (HK G36Cs have accurately hit center of mass or even head shots at 300+ meters range, and the G36C has only a 9" barrel and with the stock folded is shorter than a MP5).

Same, of course, holds true to .300 Blackout (5.56mm shell casing shortened and loaded with .308 bullets). Though the .300 was designed mostly for suppressed use out of SBRs, supersonic loads firing the same bullet weights roughly as 7.62x39mm or somewhat heavier will be more accurate and lethal at longer ranges than say 7.62x39mm or 8x33mm, let alone .30 Carbine, due to bullet design and construction.

One big, glaring problem, though. Just like 5.56mm didn't become a thing until just before the Vietnam War, .300 Blackout only became a thing like roughly 15 years ago. So that's sort of not here or there. Even the 7.65x35mm MAS round, which was an experimental French assault rifle round designed just after World War II, wasn't around in the actual World War II or immediate pre-war eras. Though that round though digital reconstruction based on it's specs has been called the post-World War II French .300 Blackout.

Point still IMO is that .30 Carbine isn't a true assault rifle round. It's basically a PDW round, the same as if someone made a .357 Mag autoloading carbine in World War II, and the came basic class of rounds that the 4.6x30mm HK or the 5.7x28mm FN are today, and the HK MP7 and the FN P90 are basically modern equivalents of what the M1/M2 carbines were originally envisioned for. A weapon for support troops and others who can't carry a full-sized rifle with them at all times.

And yes, the .30 Carbine does produce a ton more energy up close out of a rifle length barrel than .45 ACP would. But that's what the objective was. The .351 WSL would've been a better early assault rifle round as far as something "off the shelf" back then. M1907 Winchester SLs were even used by the French during World War I as PDWs or substitute standard issue rifles for second line troops and such.

 

[Alan Stevens]

And yes, the .30 Carbine does produce a ton more energy up close out of a rifle length barrel than .45 ACP would. But that's what the objective was. The .351 WSL would've been a better early assault rifle round as far as something "off the shelf" back then. M1907 Winchester SLs were even used by the French during World War I as PDWs or substitute standard issue rifles for second line troops and such.

The M16 was intended to replace four pre-existing infantry weapons with one weapon. Those were the main battle rifle, the squad automatic rifle, the submachine gun, and the semi-auto carbine.

So regarding the M1 Carbine it was basically supplanted by the 1960s.

 

[BarnOwlLover]

That's not quite here or there for World War II (even if World War II was sort of the genesis of that). And it sounds more like you're thinking of the M14--the 7.62mm NATO/.308 Win. rifle that US Army Ordinance hoped would replace 4 weapons--the M1 Garand, the M1/M2 carbines, the BAR and the Thompson M1928A1/M1/M1A1 and M3/M3A1 SMGs. It failed at the last three was was often held inferior to the M1 Garand as a service rifle aside from having detachable mags and firing NATO standard ammo.

How the AR-15 got it's foot in the door was when Curtis Le May decided that the a select fire version of the AR-15 should replace USAF MPs' M1/M2 carbines and Thompson and M3 SMGs. Then the DOD decided to shut down Springfield Armory as a manufacturer of weapons and transfer all US small arms production to the private sector, and the AR-15 (now as the XM16) was intended to be a stop gap until the SPIW program produced something useful (it didn't, nor did the subsequent ACR program, nor the OICW/XM29 program, which then became the XM8 program--closest program so far to really replace the M16/M4 family of rifles--and the XM25 semi-auto grenade launcher). And yes, there's the XM7/XM250 programs, and while IMO the XM250 may be a useful LMG for SOF use, the XM7 rifle is almost the M14 program repeating itself.

IMO, I do believe that history showed that the T48 (FN FAL) was the better of the main T40 series rifles that were intended to replace the M1 Garand. And that's still sort of not saying much--.308 Win is still basically as powerful or more so than 8mm Mauser and similar ballistically to .30-06. And the T20 select fire M1s showed that adding a selector switch to a full power rifle doesn't make a good assault rifle or LMG.

And in application, the M16 did make the M1/M2 carbines obsolete and the M14 obsolescent, but then by the 1990s there was the M4 carbine (short barreled M16), after previous attempts at a SBR/carbine version of the M16 dating back to the Colt XM177 Commando from Vietnam.

 

[BarnOwlLover]

How about something like say the AR-12? This little-known rifle was designed by Eugene Stoner at Armalite (one of his last designs before he and Jim Sullivan went to Cadillac Gage to work on the Stoner 63 rifle/MG family) as a "value oriented" version of the AR-10 that relied less on aluminum forgings and more on sheet metal stampings. There were two problems, one that was addressed during the design, and one that called for a redesign of the AR-12.

One, the AR-12 initialy used the AR-10 and AR-15 direct impingement/internal piston gas system. However, Stoner, Sullivan and Armalite sold the rights to the AR-15 to Colt in 1957, and couldn't just re-use the DI system without licensing it back from Colt, or renegotiating the licensing agreement. So the AR-12 was adapted to use a short stroke gas piston similar to the Tokarev SVT-38 and SVT-40 rifles and also copied by Walther on the G43 rifle, and Mauser on the Gerat 03 and original Gerat 06 rifles.

Second issue is that though the AR-12 was cheaper than the AR-10 and relied heavily on sheet metal stampings, it was judged to be not cheap enough in the end to pursue. So Stoner, just before leaving Armalite, designed the less expensive but very similar AR-16, which Art Miller took the basic design and scaled it down from 7.62mm NATO to 5.56mm to make the AR-18/AR-180.

Could an simplified AR-12 in an intermediate cartridge be a good carbine or early assault rifle for World War II? And by simplified I mean maybe changing the bolt from a multi-lug bolt to say a two-lug bolt like on a M1 or even an AK (swapping plunger ejector to fixed, receiver mounted blade ejector like an AR or the StG44 or FAL, thought the latter two used tilting bolts instead of rotating bolts).


View: https://www.reddit.com/r/ForgottenWeapons/comments/1guv3bp/armalite_ar12/

https://smallarmsreview.com/wp-content/uploads/2020/04/004-1.jpg

From the collection of Reed Knight and Knight's Armament/Institute of Military Technology (top to bottom, 2 AR-17 shotguns, AR-12 prototype, both AR-16 prototypes, and an AR-10A):

https://www.sturmgewehr.com/bhinton/ReedKnightCollection/AR16%27s.jpg

https://americansocietyofarmscollectors.org/wp-content/uploads/2022/10/Knight-Eugene-Stoner-design-and-guns-before-the-M16-v125.pdf