ww2 AHC: ideal SMG

You know the drill - how shoud the best-possible/ideal submachine gun for the armed forces of ww2 looked like? The desirable characteristics include manageable weight & bulk, resonable controlability & accuracy when firing bursts, suitability for mass production etc. You can 'invent' a new cartridge, or use an existing cartridge from post-ww2, for best compromise between muzzle velocity and bullet weight.
 
The Owen is pretty much the perfect frontline SMG. Reliable, decently accurate, good ergonomics, easy to make and mass produce (with none of the 'file to fit' nonsense that plagued too many austere SMGs like the Sten and PPSh-41). A PPS-43 with completely interchangeable parts, i.e. no 'file to fit' parts, would be pretty close.
 

Deleted member 1487

You know the drill - how shoud the best-possible/ideal submachine gun for the armed forces of ww2 looked like? The desirable characteristics include manageable weight & bulk, resonable controlability & accuracy when firing bursts, suitability for mass production etc.
Didn't you do a thread about this a few months ago?


You can 'invent' a new cartridge, or use an existing cartridge from post-ww2, for best compromise between muzzle velocity and bullet weight.
Colt MARS:
https://en.wikipedia.org/wiki/Colt_MARS
Nothing technically impossible about the round or weapon system in WW2 if the idea is had by then.

Arguably just a more refined idea of the Carbine in .22 Spitfire:
https://en.wikipedia.org/wiki/.22_Spitfire

Just have a full auto version in a heavier weapon for controllability:
 
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Try to imagine an Owen SMG with the trigger moved to the front pistol grip. Discard the rear pistol grip and butt stock. Make up the length with a 19" barrel. Overall length would still about the same as an extended Sterling (28"). The longer barrel would increase muzzle velocity by 12 percent and muzzle energy by up to 44 percent. Increased muzzle energy would keep traditional pistol ammo (7.62mm Tokarev, 9mm Luger, .45 ACP) viable at longer ranges.
Fixed sights are offset the left of the magazine and are calibrated for 100 to 300 yards/metres. For fighting around corners, it might need a second set of sights along the right side.
The key to installing a longer barrel without increasing overall length is a bullpup configuration with the magazine located behind the trigger. If you use a wrap-around breechblock (ala. Uzi) the trigger mechanism could impinge on the (overlapping) front end of the bolt, shortening and simplifying the trigger mechanism. Simple construction is a driving goal. Keep it simple with a fixed firing pin. Most components are pressed sheet steel (automotive industry). Limit precise machining to: barrel, bolt face, extractor and a few trigger components. The precisely-machined bolt face is squeezed (or spot-welded) into the (thick sheet steel) bolt body. The trigger bar/strap works in tension to pull down the primary sear.
Install just enough wood, Bakelite, leather or canvas to prevent soldiers' hands from freezing to the gun during chilly ambushes.

Not sure if it needs to fire single shots from a closed bolt ?????? In that case, the firing mechanism would resemble the internals of a semi-auto Uzi with the main spring(s) driving the firing pin.

Not sure if it needs a selector switch. ???? Single shot is mainly used during initial training or police work. If a selector switch is installed, it should be installed within thumb reach of the trigger hand. Similarly, if a primary safety is installed, it should be incorporated with the selector switch and rotate forward to fire. Rotating allows the soldier to confirm selector/safety position in the dark.

Definitely install a grip safety on the pistol grip with its own, separate sear. The secondary sear can engage several notches in the bottom of the bolt, reducing the risk of accidental discharge.

A top-mounted magazine (aka. Owen) could eject straight down, eliminating grumbling from left-handlers. For reliability, limit magazines to 10 or 30 round boxes with double row and double feed. When not firing, the mag and mag-well pivot forward to lay along the barrel, easing movement (for support troops: artillery, sappers, signallers, etc.). Add a dummy mag-well to carry a second mag. A dust cover protects the mag-well when folded. Similarly, the ejection port has a spring-loaded dust cover similar to an AR-15.
Add a stud or ring to hang the gun from a belt, (vehicle) bracket or shoulder strap. Pressing with one finger disconnects the ring for "quick draw."

A stamped sheet steel receiver (aka. M3 "Grease Gun") would reduce parts-count. But the bolt and recoil springs slide on two rods (ala. Uzi). To reduce opportunities for dust, the cocking handle slides along the top of the forearm and pushes a (non-reciprocating) rod that impinges on the front face of the bolt. The rod slides through a hole adjacent to the chamber.
A tubular (or stamped sheet metal aka. PPSH) barrel shroud/breech could simplify construction. A bayonet lug - on the muzzle end - would be handy when fighting in someone's house (FISH) .... if you run out of ammo before running out of bad guys. Just use a standard bayonet already issued with service rifles (e.g. spike bayonet for Commonwealth troops).

The forearm includes a socket for a (already widely issued) flashlight such that the switch falls readily to the forward hand.

If you really want to get futuristic, hang a grenade launcher under the barrel. Limit grenades to baseball size (aka M79 Blooper).
 
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Toraach

Banned
The desirable characteristics include manageable weight & bulk, resonable controlability & accuracy when firing bursts, suitability for mass production etc.
From those traits the most important is a suitability for mass production. For the rest of them, a moderate level is sufficent. SMGs were used during IIWW as personal defence weapons and as a cheap subsitutute to a supressing fire during assault on close quater combat, because light machine guns were never enough, or too heavy, and except germans in the lat war, noone had assault riffles. So I think that the best was PPS-43, cheap, and with good other characteristics. From other guns two might be on a close level. M3 Grease Gun but in a slighthly diffrent characterictis, I mean made for 9mm parabellum and with double feeding magazine (or whatever that's called in English). My other candidate is Sterling, light, handy, short, with a good magazine. I know this was made after the war, but first prototypes were completed during the war, but because Sten in production, they didn't want to change factories into making a diffrent gun during wartime. Well, magazines were importants, because they caused most problems. For M3 magazines with single feeding systems, were problematic, and the main disadvantage of this gun. PPS43 and Sterling had good, reliable mags.
 
An interesting type of ammo might've been the very much necked down 'pistol' ammo, down to 5.5mm-6.5mm. Like the current 6.5mm x 22, that uses 9 x 19 as basis. Muzzle velocities rage from sub-sonic heavy bullets (for use in supressed guns) up to lightweight ammo that can do 3000 fpm(!). Again, nothing that can't be done back in 1930s/40s for the ww2. link
 

Deleted member 1487

An interesting type of ammo might've been the very much necked down 'pistol' ammo, down to 5.5mm-6.5mm. Like the current 6.5mm x 22, that uses 9 x 19 as basis. Muzzle velocities rage from sub-sonic heavy bullets (for use in supressed guns) up to lightweight ammo that can do 3000 fpm(!). Again, nothing that can't be done back in 1930s/40s for the ww2. link
https://en.wikipedia.org/wiki/.221_Remington_Fireball
The 6.5mm CBJ relies on a special sabot that couldn't exist with WW2 tech.
 
Russian ones a crude, the Thompson was an obscenely heavy weapon for the range and caliber. The grease gun has issues as does the Sten. For the Allies I have to go with the Owen and then the Suomi and then the MP-38/40.
 
An interesting type of ammo might've been the very much necked down 'pistol' ammo, down to 5.5mm-6.5mm. Like the current 6.5mm x 22, that uses 9 x 19 as basis. Muzzle velocities rage from sub-sonic heavy bullets (for use in supressed guns) up to lightweight ammo that can do 3000 fpm(!). Again, nothing that can't be done back in 1930s/40s for the ww2. link

The .38/45 Auto, a Wildcat cartridge of the '60s, could have been done anytime after the .45APC was developed.

It's pretty much a .45ACP necked down to .357 diameter.

130 gr(8g) FMJ 1,245 ft/s (379m/s) 445 ft⋅lbf (603 J)

Pretty much 9mm Magnum performance in a shorter cartridge and lower pressure

Put that in a M3A1 Grease Gun that uses Thompson mags
Done. You have a flatter shooting cartridge that keeps the low cyclic rate that made it so easy to shoot.
Only thing to add would be a more robust folding stock
 

Deleted member 1487

Saboted rounds are not the only choice. From the article we can see, for example, that bullets that weight 115 gr are also offered, as well as the 38.6 gr ones.
Might not be bad, but a lot depends on the muzzle velocity and energy retention. A necked down .30 carbine round might be better for that caliber of bullet.

A flat base 7.92 or 7.62 in CETME CSP-003 configuration (bakelite nose filling, lead tail) might be better:
http://www.municion.org/762x51/762x51Esp.htm
csp003G.jpg


7.3 grams, aerodynamic, and designed to tumble means it could be pushed to faster speeds than a 9mm round, retain energy just as well if not better, and transfer more energy to the target than a bigger caliber through tumbling.

Maybe a bullet shaped like the British .280?
7mm_mk1.jpg
 
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Might not be bad, but a lot depends on the muzzle velocity and energy retention. A necked down .30 carbine round might be better for that caliber of bullet.

A flat base 7.92 or 7.62 in CETME CSP-003 configuration (bakelite nose filling, lead tail) might be better:
http://www.municion.org/762x51/762x51Esp.htm
7.3 grams, aerodynamic, and designed to tumble means it could be pushed to faster speeds than a 9mm round, retain energy just as well if not better, and transfer more energy to the target than a bigger caliber through tumbling.

Maybe a bullet shaped like the British .280?

For the comparison sake, the 7.62 Tokarev was pushing a 5.5-5.8 g bullet at up to 520 m/s. The 7.9 Kurtz was of 8 g bullet, MV of 685 m/s. M1 Carbine .30 ammo - 7 g at 605 m/s. So yes, the 7-7.5 g at 650-700 m/s will work, but not in a sub-machine gun. Such a powerful cartridge needs some means of locking the bolt until the pressure is down to an acceptable level, as it was the case with M1 Carbine or the StG-44, unlike the pistol-based or derived cartridges where a good spring and not overly heavy bolt will do the job.
I agree with you that the weapon based on the M1 Carbine that uses a necked-down .30 Carbine ammo would've been a good, if not a great idea. But that would've been an assault rifle, not a SMG. With folding stock, as some versions of the carbine got historically, it might've even make SMGs redundant for the US army. Perhaps the SMGs would've been just a niche weapon for tank crews and special forces of the US military?
SMGs will be cheaper and faster to manufacture, so the US industry can help their Allies to ramp up their stocks of automatic weponry.
 

Deleted member 1487

For the comparison sake, the 7.62 Tokarev was pushing a 5.5-5.8 g bullet at up to 520 m/s. The 7.9 Kurtz was of 8 g bullet, MV of 685 m/s. M1 Carbine .30 ammo - 7 g at 605 m/s. So yes, the 7-7.5 g at 650-700 m/s will work, but not in a sub-machine gun. Such a powerful cartridge needs some means of locking the bolt until the pressure is down to an acceptable level, as it was the case with M1 Carbine or the StG-44, unlike the pistol-based or derived cartridges where a good spring and not overly heavy bolt will do the job.
I agree with you that the weapon based on the M1 Carbine that uses a necked-down .30 Carbine ammo would've been a good, if not a great idea. But that would've been an assault rifle, not a SMG. With folding stock, as some versions of the carbine got historically, it might've even make SMGs redundant for the US army. Perhaps the SMGs would've been just a niche weapon for tank crews and special forces of the US military?
SMGs will be cheaper and faster to manufacture, so the US industry can help their Allies to ramp up their stocks of automatic weponry.
Why does it have to have a simple blowback system? The Hungarian 43M had a lever delayed system and a MAS49 style direct impingement/tilting bolt system would work just as well if not better. SMGs were effectively replaced entirely by the assault rifle, so IMHO the best SMG is an assault rifle of the M4 Carbine variety (hence my pushing the .221 fireball...which is effectively a .22 spitfire).

I'd say .22 Spitfire with a direct impingement gas system like the French MAS49 in a Hyde 33 SMG layout with a folding stock.
 

Deleted member 1487

For the comparison sake, the 7.62 Tokarev was pushing a 5.5-5.8 g bullet at up to 520 m/s. The 7.9 Kurtz was of 8 g bullet, MV of 685 m/s. M1 Carbine .30 ammo - 7 g at 605 m/s. So yes, the 7-7.5 g at 650-700 m/s will work, but not in a sub-machine gun. Such a powerful cartridge needs some means of locking the bolt until the pressure is down to an acceptable level, as it was the case with M1 Carbine or the StG-44, unlike the pistol-based or derived cartridges where a good spring and not overly heavy bolt will do the job.
I agree with you that the weapon based on the M1 Carbine that uses a necked-down .30 Carbine ammo would've been a good, if not a great idea. But that would've been an assault rifle, not a SMG. With folding stock, as some versions of the carbine got historically, it might've even make SMGs redundant for the US army. Perhaps the SMGs would've been just a niche weapon for tank crews and special forces of the US military?
SMGs will be cheaper and faster to manufacture, so the US industry can help their Allies to ramp up their stocks of automatic weponry.
Wait slow up. You were just talking about this:
An interesting type of ammo might've been the very much necked down 'pistol' ammo, down to 5.5mm-6.5mm. Like the current 6.5mm x 22, that uses 9 x 19 as basis. Muzzle velocities rage from sub-sonic heavy bullets (for use in supressed guns) up to lightweight ammo that can do 3000 fpm(!). Again, nothing that can't be done back in 1930s/40s for the ww2. link

http://www.sadefensejournal.com/wp/?p=625

Saboted rounds are not the only choice. From the article we can see, for example, that bullets that weight 115 gr are also offered, as well as the 38.6 gr ones.

7.3 grams is 112 grains, i.e. lighter than the 6.5mm bullet you were talking about!!! Lighter than a .45 and 9mm. Using a flat based composite core bullet in the Tokarev 7.62x25mm or necked down 9x25mm Mauser would have been just fine and work just as well if not better than the 115 grain 6.5mm you were pushing for the same cartridge!

Using the historical 150 grain flat based 'proof' bullet for the .30 carbine as a platform and altering the replacing half the lead with bakelite would reduce the weight to 100 grains and allow for it to be pushed in the velocity range of a very hot 9mm parabellum round, while being designed to retain energy better than tumble more readily.
30CarbProofB.JPG
 
The .38/45 Auto, a Wildcat cartridge of the '60s, could have been done anytime after the .45APC was developed.

It's pretty much a .45ACP necked down to .357 diameter.

130 gr(8g) FMJ 1,245 ft/s (379m/s) 445 ft⋅lbf (603 J)

Pretty much 9mm Magnum performance in a shorter cartridge and lower pressure

Put that in a M3A1 Grease Gun that uses Thompson mags
Done. You have a flatter shooting cartridge that keeps the low cyclic rate that made it so easy to shoot.
Only thing to add would be a more robust folding stock
You could have a Thompson in .351 or .45 Remington-Thompson, though the latter would be rather heavy for it's level of power.
 
Sterling SMG - Hot 9mm x 19 Para

Briliantly Simple. Indestrucable. Highly dirt resistant. High Quality finish. Robust folding stock making for a very compact weapon ideal for Paratroopers and AFV crews. Very reliable and robust magazine (often the weak link in any firearm). Controlable recoil - accurate to 200 meters. Very simple to clean. Very light. Looks cool as $%^&.
 

SwampTiger

Banned
I think the French 8x35 Ribeyrolles Modele 1918 using a locked breech would have killed the SMG. In regard to the OP, I like a Sterling, PPS43 or Beretta M38/42. I would prefer the Sterling or Beretta if they were able to convert to 7.63 Tokarev or Mauser. Use a 100-110 grain spitzer soft-steel bullet with a lead base section.
 
Why does it have to have a simple blowback system? The Hungarian 43M had a lever delayed system and a MAS49 style direct impingement/tilting bolt system would work just as well if not better. SMGs were effectively replaced entirely by the assault rifle, so IMHO the best SMG is an assault rifle of the M4 Carbine variety (hence my pushing the .221 fireball...which is effectively a .22 spitfire).

I'd say .22 Spitfire with a direct impingement gas system like the French MAS49 in a Hyde 33 SMG layout with a folding stock.

Simple blowback sistem for SMGs is advantage, not disadvantage. Gives you automatic fire ona budget, provided the cartridge used is not overpowered. The 43M needed the delayed blowback since it used the more powerful 9x25 cartridge - the simple blowback will not cut it. The M1/M2 carbine was also too powerful for simple blowback.
I'd again say that .22 Spitfire on the M2 carbine is a very good idea.

Wait slow up. You were just talking about this:
http://www.sadefensejournal.com/wp/?p=625
7.3 grams is 112 grains, i.e. lighter than the 6.5mm bullet you were talking about!!! Lighter than a .45 and 9mm. Using a flat based composite core bullet in the Tokarev 7.62x25mm or necked down 9x25mm Mauser would have been just fine and work just as well if not better than the 115 grain 6.5mm you were pushing for the same cartridge!

Using the historical 150 grain flat based 'proof' bullet for the .30 carbine as a platform and altering the replacing half the lead with bakelite would reduce the weight to 100 grains and allow for it to be pushed in the velocity range of a very hot 9mm parabellum round, while being designed to retain energy better than tumble more readily.

123 gr/8g bullet for the 6.5 CBJ is a subsonic bullet, the Tokarev was almost 1.5 Mach. I certainly don't advocate it, and I would not use such a heavy bullet for the necked down 9mm or 7.62 Tokarev, but someting at ~60-70 gr/ with MV of 650-600 m/s.
Again, the variations of the .30 Carbine are good things, but not for SMG due to being too powerful.
 
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