M1 Carbine as potential US WW2 assault rifle

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Deleted member 1487

http://www.sandygunworks.com/Articles/The57JohnsonSpitfire.aspx
I was recently made aware of the .22 version of the M1 carbine developed in the early 1960s made by necking down the existing M1 carbine's .30 caliber cartridge with a 5.7mm bullet on the end achieving an intermediate assault rifle cartridge velocity of between 2700-3000 fps. With the M2 carbine automatic conversion it seems to me that the M1 Carbine could have been a genuine assault rifle in WW2, perhaps predating the StG 44 had right ideas been had. The smaller round is a minor modification to the existing weapon and making and automatic version is a mechanism modification, otherwise it would be basically the same weapon that existed in 1941. How could we potentially get an automatic 5.7mm necked down version of the M2 carbine ready for WW2? What impact would such a weapon have had?
 
I understood that the M1 carbine was originally supposed to be capable of select fire during development but this function was dropped during initial manufacture and the later M2 and field conversion kits for the M1 restored this feature much later in the war - so a simpler POD to get a select fire M1 Carbine in 1941 is to manufacture the weapon with the original Select fire capability.

As to the round - the .30 Winchester was a development of an earlier Winchester round and given the designers were all Winchester men it made sense for them to use what they knew as this round performed to the required standards

Perhaps part of the requirement would be to penetrate a steel helmet at say 100 yards and the .30 carbine is not developed as it is perceived to not deliver the penetrative ability necessary (I have no idea if the .30 Carbine can do tis or not!) and your suggested smaller lighter but faster 5.7mm is chosen instead as it does have a greater penetration.

And/or its found that the lower velocity .30 carbine (7.62 x 33) cartridge suffers to great a bullet drop beyond 100 meters while a faster 'flatter' and necked down 5.7 x 33 has better performance beyond 100 meters.

There that should do it
 

Deleted member 1487

I understood that the M1 carbine was originally supposed to be capable of select fire during development but this function was dropped during initial manufacture and the later M2 and field conversion kits for the M1 restored this feature much later in the war - so a simpler POD to get a select fire M1 Carbine in 1941 is to manufacture the weapon with the original Select fire capability.

As to the round - the .30 Winchester was a development of an earlier Winchester round and given the designers were all Winchester men it made sense for them to use what they knew as this round performed to the required standards

Perhaps part of the requirement would be to penetrate a steel helmet at say 100 yards and the .30 carbine is not developed as it is perceived to not deliver the penetrative ability necessary (I have no idea if the .30 Carbine can do tis or not!) and your suggested smaller lighter but faster 5.7mm is chosen instead as it does have a greater penetration.

And/or its found that the lower velocity .30 carbine (7.62 x 33) cartridge suffers to great a bullet drop beyond 100 meters while a faster 'flatter' and necked down 5.7 x 33 has better performance beyond 100 meters.

There that should do it
That seems remarkably simple to get the solution. So what would an American assault rifle mean to WW2 (and beyond) from 1942 on? Would we even see an M16 or would this continue to evolve like the M14 evolving from the Garand? The smaller, perhaps even more pointed 5.7mm round would be effective out to 300m or more (the Spitfire round is still somewhat rounded like a piston round and isn't as well aerodynamically honed as say the Soviet 5.45mm or other later sub-6mm assault rifle rounds) while having high wound potential like the sub-6mm caliber rounds developed from the 1960s on for mid-Cold War ARs. Plus of course they could carry a lot more ammo.
 
That seems remarkably simple to get the solution. So what would an American assault rifle mean to WW2 (and beyond) from 1942 on? Would we even see an M16 or would this continue to evolve like the M14 evolving from the Garand? The smaller, perhaps even more pointed 5.7mm round would be effective out to 300m or more (the Spitfire round is still somewhat rounded like a piston round and isn't as well aerodynamically honed as say the Soviet 5.45mm or other later sub-6mm assault rifle rounds) while having high wound potential like the sub-6mm caliber rounds developed from the 1960s on for mid-Cold War ARs. Plus of course they could carry a lot more ammo.

Perhaps with greater utility made in front line combat using this weapon (over he already considerable use of the OTL M1/M2) due to this more useful round a greater appreciation will be shown by the US with regards to post war developments of the intermediate rounds - such as the 7.92 mm Kurtz and further development of the subsequent British / Belgium leverage of the .270/.280 / 7mm British and perhaps the British round in its original lighter .270 format will be more acceptable to the US and this round is accepted as the NATO standard.

If the 5.7 round had proven to be very successful and it was better understood at the end of the war that the majority of 'Infantry' combat took place under 300 meters and the mass majority of that at or under 100 meters then the US fixation on a powerful .30 cal round would not be as entrenched!

Then the round is leveraged by weapon designs similar to those existing OTL light rifle designs - i.e. EM2, FN FAL (including Para Bullpup design) and FN MAG Designs and eventually by the AR10 platform



Probably!
 

Deleted member 1487

Perhaps with greater utility made in front line combat using this weapon (over he already considerable use of the OTL M1/M2) due to this more useful round a greater appreciation will be shown by the US with regards to post war developments of the intermediate rounds - such as the 7.92 mm Kurtz and further development of the subsequent British / Belgium leverage of the .270/.280 / 7mm British and perhaps the British round in its original lighter .270 format will be more acceptable to the US and this round is accepted as the NATO standard.

If the 5.7 round had proven to be very successful and it was better understood at the end of the war that the majority of 'Infantry' combat took place under 300 meters and the mass majority of that at or under 100 meters then the US fixation on a powerful .30 cal round would not be as entrenched!

Then the round is leveraged by weapon designs similar to those existing OTL light rifle designs - i.e. EM2, FN FAL (including Para Bullpup design) and FN MAG Designs and eventually by the AR10 platform



Probably!
Given how the US kept the M1 and it's derivatives in service for so long, if it proves even more effective and durable wouldn't they just adopt the caliber and refine the bullet and design and make it part of their NATO bi-pod (7.62 and now 5.7mm) standard calibers?
 
Given how the US kept the M1 and it's derivatives in service for so long, if it proves even more effective and durable wouldn't they just adopt the caliber and refine the bullet and design and make it part of their NATO bi-pod (7.62 and now 5.7mm) standard calibers?

Probably but only for about 40 - 60 years before they start to accept the wisdom of the intermediate round
 

Deleted member 1487

Probably but only for about 40 - 60 years before they start to accept the wisdom of the intermediate round
Well if they already have one, why wouldn't they just keep and continue to develop it?
 
Going with the Bendix-Hyde Carbine design instead of the Winchester submission might help as well:

h22C6Qc.jpg


The Bendix-Hyde Light Rifle was one of two rifles that in the first round of trials impressed testers the most, the other being Springfield Armory’s submission designed by none other than John Cantius Garand. What made the Bendix-Hyde unique among the initial entrants was its submachine gun-like appearance, having a separate pistol grip and stock – something that would become closely associated with the assault rifle concept in the latter half of the 20th Century.

But the rifle is interesting not only for its looks. The rifle with its pistol grip and sleek appearance also was a select-fire weapon, a characteristic that was originally a part of the Light Rifle solicitation. It utilized an action that combined elements from both the M1 Garand and the Browning BAR, using a doglegged direct-gas piston operating rod with nested spring in conjunction with a fixed bolt and wedge-shaped locking piece that tilted upwards into the receiver. These two elements would again be combined in the .30 Light Rifle caliber Earle Harvey-designed T25/T47 rifle as part of the Lightweight Rifle program of the 1950s.

Weighing in at 5.35 pounds unloaded with a sling and an empty 5-round magazine, the Bendix-Hyde was very light, although not quite as light as the sub-5lb Winchester entry that became the M1 Carbine. However, the Bendix-Hyde could have given substantially better performance versus the historical M1, had it been adopted. Hyde’s design practices had followed the closed-receiver design model, proven to be very dust and debris resistant. This layout suggests superior performance in adverse conditions versus open-action weapons like the M1 Carbine, and the testing at Aberdeen Proving Grounds backs up this hunch:
...In addition, remember that the magazine pattern of the M1 Carbine is very poor, being too thin and flimsy, as well as having generally poor design. It is the weak point of the M1 Carbine from a functioning perspective, and it seems very likely that the Bendix-Hyde pattern magazine would have been superior. Another detail improvement of the Hyde versus the M1 Carbine is the dust cover on the Hyde’s operating rod. This would prevent oprod dismount, the serious malfunction discussed in yesterdays article, and something that can happen to the M1 Carbine as well as the M1 Garand.

RKn2fON.jpg

http://www.thefirearmblog.com/blog/...ne-an-american-sturmgewehr-prototype-in-1941/
 
Well if they already have one, why wouldn't they just keep and continue to develop it?

I was trying to be funny - failed again

But the point is I fear you might be right - the conclusion that the Germans British/Belgians and Russians came to in developing a 'universal' intermediate round to be used in Assault rifles replacing both Rifle and SMG, and the GPMG replacing Squad LMGs and battalion Level MMGs would be ignored by the US and instead their own conclusion would be pushed on NATO!
 

Deleted member 1487

I was trying to be funny - failed again
Sorry read that too fast. Next time winky face ;)

But the point is I fear you might be right - the conclusion that the Germans British/Belgians and Russians came to in developing a 'universal' intermediate round to be used in Assault rifles replacing both Rifle and SMG, and the GPMG replacing Squad LMGs and battalion Level MMGs would be ignored by the US and instead their own conclusion would be pushed on NATO!
Well the US did that IOTL anyway, they'd just have their version of the 5.56 sooner. M14/M1 full auto carbine/AR combo. They'd probably toss in the M60 as a copy of the German model. Before doing their LMG/Minimi 5.7mm.

Edit:
Basically OTL screw ups, but an earlier, perhaps more reliable M16. Certainly it would help in the Korean War and in the Pacific in WW2, and in Vietnam compared to troubleshooting the M16. Of course if they do share them with the Soviets in WW2...do they Soviet make their own version sooner, perhaps avoiding the 7.62 for the AK and jumping right to the 5.45??? That would then make Korea and Vietnam more interesting, as a small arms war of the sub-6mm caliber ARs. The Afghans apparently did not like fighting the AK-74 because the wounds the tumbling 5.45mm round would make would result in a lot of amputations. Against Soviet supplied forces then US forces might have a lot more casualties or at least disabling injuries.

The Germans and Japanese would have a bad time in WW2 in the meantime.
 
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http://www.sandygunworks.com/Articles/The57JohnsonSpitfire.aspx
I was recently made aware of the .22 version of the M1 carbine developed in the early 1960s made by necking down the existing M1 carbine's .30 caliber cartridge with a 5.7mm bullet on the end achieving an intermediate assault rifle cartridge velocity of between 2700-3000 fps. With the M2 carbine automatic conversion it seems to me that the M1 Carbine could have been a genuine assault rifle in WW2, perhaps predating the StG 44 had right ideas been had. The smaller round is a minor modification to the existing weapon and making and automatic version is a mechanism modification, otherwise it would be basically the same weapon that existed in 1941. How could we potentially get an automatic 5.7mm necked down version of the M2 carbine ready for WW2? What impact would such a weapon have had?

Excellent idea - basically an 'almost 5.54x39' Soviet round. Very controlable, and far more accurate than a SMG.
(even the M2 Carbine would've been great, but that is beyond the OP. Hmm - how about a 6.5mm derivate?)
 

Deleted member 1487

Excellent idea - basically an 'almost 5.54x39' Soviet round. Very controlable, and far more accurate than a SMG.
(even the M2 Carbine would've been great, but that is beyond the OP. Hmm - how about a 6.5mm derivate?)
Given the parent cartridge its so low powered that you need a sub-6mm round to get the necessary muzzle velocity to make it worthwhile IMHO. Especially if you want to use a heavier, longer bullet. It can be thinner, but longer and made much more aerodynamic. With full auto you'd really rip up someone at 400m.
 
The only issue is that it isn't a sub-6mm caliber weapon. It's more like the AK-47 minus the full auto.

The Winchester design didn't use a proto-.22 Spitfire either, so it seems safe to split the question of caliber and weapon design in this instance. And the Bendix-Hyde design was select fire.
 

Deleted member 1487

The Winchester design didn't use a proto-.22 Spitfire either, so it seems safe to split the question of caliber and weapon design in this instance. And the Bendix-Hyde design was select fire.
Sure, but given the select fire option was on the table for the M1 at design, it was good to go. The 'improved' Bendix-Hyde carbines were worse than the originals, so I'm not sure that was the best route to go.
 

Deleted member 1487

BTW speaking of overweight bullets, the German 792 Kurz was actually 8.22mm thick and the entire cartridge was fatter than the standard Mauser 7,92 long. I have no idea why they didn't just slap a 7mm bullet on a necked down standard 7.92mm cartridge shortened to say 40 or 45mm.
 

Anderman

Donor
BTW speaking of overweight bullets, the German 792 Kurz was actually 8.22mm thick and the entire cartridge was fatter than the standard Mauser 7,92 long. I have no idea why they didn't just slap a 7mm bullet on a necked down standard 7.92mm cartridge shortened to say 40 or 45mm.

Most likely with the same bullet diameter they could use the same tools to make the barrels.
 
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