US semi-auto rifle program in the 1920s yields intermediate or SCHV cartridge

[Deleted member 1487]

https://en.wikipedia.org/wiki/Pedersen_rifle

Testing in the early 1920s led the Ordnance Bureau to identify three rifle designs - the Bang rifle, the Thompson Autorifle, and the primer-protrusion actuated Garand Model 1919 rifle - as promising candidates. However, all three designs were burdened with the high pressure and heat generating characteristics of the .30-06 ammunition, which looked likely to result in a weapon too heavy and too subject to overheating to be worthwhile. Trials with a small number of "militarized" .25 Remingtonautoloading rifles, despite their unsuitability for combat, provided a body of practical experience with semiautomatic rifles and an appreciation for the idea less powerful ammunition might be a critical part of the successful development of such weapons.

https://en.wikipedia.org/wiki/.25_Remington
Though significantly lower powered than the .250 Savage, I wonder if it might be possible for the US army to run with 'modernized' .25 Remington cartridge based on existing experience and have the first intermediate cartridge/assault rifle combo. Even if just for their M1 Carbine.

Interestingly that cartridge ended up producing a necked down .22 with performance and size very similar to the later 5.56 NATO...just in the 1930s-1940.

Harvey Donaldson also used the .25 Remington case in early experiments that would eventually lead to the creation of the .219 Donaldson Wasp. Donaldson later switched his experimentation to Winchester .219 Zipper brass after the launch of that cartridge in 1937.

https://en.wikipedia.org/wiki/.219_Donaldson_Wasp

53 gr (3 g) Sierra 3,465 ft/s (1,056 m/s) 1,413 ft⋅lbf (1,916 J)

https://en.wikipedia.org/wiki/.219_Zipper

55 gr (4 g) Nosler Spitzer boat tail 3,097 ft/s (944 m/s) 1,172 ft⋅lbf (1,589 J)

 

[tomo pauk]

...
Though significantly lower powered than the .250 Savage, I wonder if it might be possible for the US army to run with 'modernized' .25 Remington cartridge based on existing experience and have the first intermediate cartridge/assault rifle combo. Even if just for their M1 Carbine.

Interestingly that cartridge ended up producing a necked down .22 with performance and size very similar to the later 5.56 NATO...just in the 1930s-1940.
...

Make a spitzer bullet, 80-100 gr, and there you go. Or, neck it down to .22 and there is a SCHV.
Either way, a low-recoil ammo that is well suited for carbines (even if there will not be a 10 lb carbine with any of those rounds), semi-autos, full-autos and light machine-guns.
With case length retained and necked down to .22 - the early .224 Valkyre?

 

[Cryhavoc101]

While not wanting to detract from your good work here remember that one of the criteria that must still be appreciated for a principle long arm round is the ability to kill a horse as cavalry was still a thing right up to WW2 when it suddenly wasn't.

Just saying.

 

[Deleted member 1487]

Make a spitzer bullet, 80-100 gr, and there you go. Or, neck it down to .22 and there is a SCHV.
Either way, a low-recoil ammo that is well suited for carbines (even if there will not be a 10 lb carbine with any of those rounds), semi-autos, full-autos and light machine-guns.
With case length retained and necked down to .22 - the early .224 Valkyre?

That is something I was thinking in terms of the .22 option. Even a 5 gram .22 bullet (77 grain) would have excellent performance out of that cartridge case with it's weaker powders (even better with IMR) within 600m (about 125m more than cited effective range of the M1 Garand) and would be pretty stellar out of an automatic rifle. In fact it might even offer better performance than the current 5.56x45 with a 5 gram bullet.

Of course IOTL the US military was still stuck in the idea of 'bigger bullets make bigger holes', so it would be hard to get adopted, but given that they were already experimenting with fast, light 6.5mm cartridges and civilians were experimenting with SCHV .22 rounds its not totally inconceivable for carbine type weapon, especially if the cartridge is cut down and a light bullet used.

I did a thread a couple of years ago about the M1 Carbine getting the assault rifle treatment with a .22 caliber round:
https://www.alternatehistory.com/forum/threads/m1-carbine-as-potential-us-ww2-assault-rifle.412963/

This POD would be a different situation though, as they were already working with the .25 Rem in the 1920s and could potentially look into making a carbine with it or something similar.

While not wanting to detract from your good work here remember that one of the criteria that must still be appreciated for a principle long arm round is the ability to kill a horse as cavalry was still a thing right up to WW2 when it suddenly wasn't.

Just saying.

Ha, ninja-ed me while I was writing about that. I'm thinking though it might be possible for an M1 carbine type weapon, which used a light bullet/cartridge/rifle combo that certainly wasn't going to be hurting a horse even at 100m.

 

[Cryhavoc101]

Ha, ninja-ed me while I was writing about that. I'm thinking though it might be possible for an M1 carbine type weapon, which used a light bullet/cartridge/rifle combo that certainly wasn't going to be hurting a horse even at 100m.

Maybe that is the reason for a SCHV round out of an M1 carbine analogous weapon - it uses high MV to achieve 'Horse Hurtin' damage at 100m?

 

[tomo pauk]

While not wanting to detract from your good work here remember that one of the criteria that must still be appreciated for a principle long arm round is the ability to kill a horse as cavalry was still a thing right up to WW2 when it suddenly wasn't.

Just saying.

Was that a requirement also issued by US Army?

 

[Deleted member 1487]

Maybe that is the reason for a SCHV round out of an M1 carbine analogous weapon - it uses high MV to achieve 'Horse Hurtin' damage at 100m?

The M1 Carbine was more a "kill German paratroopers out to 200m" weapon. Thing is with that goal a SCHV weapon is far better than the .30 carbine due to how much lower recoil they are, as well as the ammo and rifle being lighter. Thing is why did they reinvent the wheel when the military already had an intermediate cartridge and rifle combo in the 1920s? Even the police had a special model of the Remington rifle in the 1930s. No need to invent a new rifle or ammo, but apparently it did need to be 'militarized' to make it more resilient to the elements in a military situation.

 

[Cryhavoc101]

The M1 Carbine was more a "kill German paratroopers out to 200m" weapon. Thing is with that goal a SCHV weapon is far better than the .30 carbine due to how much lower recoil they are, as well as the ammo and rifle being lighter. Thing is why did they reinvent the wheel when the military already had an intermediate cartridge and rifle combo in the 1920s? Even the police had a special model of the Remington rifle in the 1930s. No need to invent a new rifle or ammo, but apparently it did need to be 'militarized' to make it more resilient to the elements in a military situation.

In the 1920s there is no need for a "kill German paratroopers out to 200m" weapon

However maybe there is a battle in WW1 that involved rear echelon troops stopping front line enemy troops from breaking through - sort of like what happened in Michael

So a weapon that allows non riflemen to fight effectively against 'Stormtroopers'?

 

[Deleted member 1487]

In the 1920s there is no need for a "kill German paratroopers out to 200m" weapon

Sure, but in the late 1930s when the M1 Carbine was ordered there was. And there were guns already capable of that.
https://en.wikipedia.org/wiki/M1_carbine#Limitations_of_weapons_in_the_U.S._arsenal

However maybe there is a battle in WW1 that involved rear echelon troops stopping front line enemy troops from breaking through - sort of like what happened in Michael

So a weapon that allows non riflemen to fight effectively against 'Stormtroopers'?

A variety of 'shorter' ranged carbine trench guns were used that were effectively militarized civilian US hunting rifles.
https://www.thefirearmblog.com/blog/2013/07/23/semiauto-rifles-wwi/
Number #1 is the Remington Model 8.
The Winchester SLRs were usable too if modified for the .25 Remington...which Winchester was unlikely to do unless there was a pressing reason...like a military contract. The French military used them in the trenches and they were well liked.
https://en.wikipedia.org/wiki/Winchester_Model_1907

During World War I, when the French Army ordered 2,800 rifles which they then modified for fully automatic fire and doubled the magazine size in 1917.[3]

The police also were fans of the rifle. The .25 caliber allows for the rifle being made even lighter, though if they went down to a .22 caliber with the .25 Rem case and stuck to a 4-5 gram bullet they could approach OTL M1 Carbine weight, though due to the simple blowback system it would probably be heavier and harder recoiling, but much simpler to make.

Ironically Winchesters M2 carbine prototype used parts of the Model 1907 and Garand:
https://www.wideopenspaces.com/check-interesting-winchester-m2-prototype-carbine/

 

[Deleted member 1487]

Or I suppose if they go the Winchester route they could just neck down the .351 WSL to .257 bullets. IIRC the US Army 'Pig Board' used an 8 gram flat based spitzer 6.5mm bullet in it's lethality studies, so using that bullet on the .351 WSL yields a bottle necked cartridge with a bullet 33% lighter than the parent, which I'd imagine get a muzzle velocity at least 15-20% higher than parent. At 570m/s for the .351 WSL yields at least 655m/s for the .257 8 gram bullet, which is significantly better than the .30 Carbine/M1 Carbine combo, plus higher energy for down range effect. If they reduced that down to say 6 grams, then you might well be getting over 700m/s and effective out to 2-300m. It would also really help on the recoil, as one of the main factors is apparently bullet weight, which would then allow for the gun to be modified to be considerably less heavy.

 

[marathag]

Was that a requirement also issued by US Army?

being able to kill a horse wasn't exactly specified, but was very interested in pine board penetration at 1000 yards, a test that dated back to the introduction of the Minie Ball, where it was 'accepted knowledge'
that if a round could penetrate a 1" thick, dry, rough cut Pine board, that would also kill a man. The .58 penetrated 3 1/4" at 1000 yards. Most tests were set with a 1" spacing between boards

In 1879 with the Sandy Hook shooting trials at 2,500 yards, the .45-70-405 service load was 1.12 inches, the Martini-Henry .45-85-480 with 2.50 inches, and the long range Springfield .45-80-500 5.25".

In 1906, the replacement of the .30-03 was noted that while the new 150 grain new bullet penetrated the same amount of Pine at 1000 yards, and double at 500.

Last ones I know of to use the pine board criteria was some 5.56mm testing in the early '70s

 

[SwampTiger]

As a proponent of an early .30 Remington based intermediate round, I have been a fan of the .25 Remington and similar derivatives. For a modernized, smaller caliber Remington based round, you should look at the .401 Winchester to 6.8 SPC comparison. Similar cartridge base which was beefed up and slightly lengthened. The 6.8 SPC pressures are substantially higher than the .401 WSL, SAAMI 55,000 psi versus 37-39,000 psi. A 6.5 mm variant with a longer OAL to the 6.8 SPC would provide reasonable velocities with a steel cored spitzer boat tailed bullet in the 125 to 140 range.

 

[Deleted member 1487]

As a proponent of an early .30 Remington based intermediate round, I have been a fan of the .25 Remington and similar derivatives. For a modernized, smaller caliber Remington based round, you should look at the .401 Winchester to 6.8 SPC comparison. Similar cartridge base which was beefed up and slightly lengthened. The 6.8 SPC pressures are substantially higher than the .401 WSL, SAAMI 55,000 psi versus 37-39,000 psi. A 6.5 mm variant with a longer OAL to the 6.8 SPC would provide reasonable velocities with a steel cored spitzer boat tailed bullet in the 125 to 140 range.

The big issue with those sorts of rounds it the rimmed cartridge. You'd need to at least remove the rim as a starter before even looking at necking down.
That said I do wonder if the bottlenecking would increase pressure even with the same powder. Still, I think a flat base bullet would be the way to go so as not to reduce powder capacity any more than necessary given that the performance would really not require ranges beyond 300m. A 90 grain bullet, perhaps a shorter version of the 125 grain design with a steel core, is about 6 grains, so saving half the weight of the .401 Winchester cartridge could yield a muzzle velocity of 800m/s (assuming a 20 inch barrel, it might be less with a 18 inch like the M1 Carbine). Performance would probably be weak out to 300m with a flat base and 90 grain weight, but within 200m it would hit pretty hard and be quite flat firing, easily besting the .30 carbine cartridge/bullet.

 

[SwampTiger]

The .30 Remington family is rimless. The .401 WSL is semi-rimmed. Remove the tiny rim.

The 6.8 SPC sends a 110 grain bullet out at 780-850 m/s ( 2550-2800 f/s) from a 20 inch barrel. Note the cartridge was optimized for the M16 max COL.

 

[Deleted member 1487]

The .30 Remington family is rimless. The .401 WSL is semi-rimmed. Remove the tiny rim.

The 6.8 SPC sends a 110 grain bullet out at 780-850 m/s ( 2550-2800 f/s) from a 20 inch barrel. Note the cartridge was optimized for the M16 max COL.

Part of the issue is mixing Remington and Winchester rifles and ammo. I don't know how hard it would be to modify, but I would think it wouldn't be too hard to remove the rim. I'd imagine that an 18 inch barrel would be the limit, as that was the M1 Carbine's length. The WW1 model had a box mag and a pistol grip; I'm not going to post the photo, it's too big, but here is the link: https://i.ytimg.com/vi/MJtaUyYNNgc/maxresdefault.jpg
It lacks a stock, but I'd imagine you could add something like the M1 Carbine para model with a side folding wire stock. With a slightly cut down barrel and probably general lightening of the modified model with a .257 bullet on the .401 non-rimmed case it would probably still be heavier than the M1 Carbine, but much more capable and potentially shorter overall with a folding stock.

 

[SwampTiger]

The blowback Winchesters were heavy. Their forestocks readily cracked due to thin wood because of an ungodly large weight to properly operate the action. The cocking rod was inconvenient. Add a short gas system and a rotary bolt to allow a substantial weight reduction,and voila, a sort-of carbine. The bank robbers of the thirties used these Model 1907's and Remingtons in various cut down versions. Police variants included bayonets and larger magazines.

All the pieces were there for Springfield, Winchester or Remington to develop such a gun in the 20's. The French were nearly there with the Ribeyrolles 1918.

 

[AJE]

Thing is why did they reinvent the wheel when the military already had an intermediate cartridge and rifle combo in the 1920s? Even the police had a special model of the Remington rifle in the 1930s. No need to invent a new rifle or ammo, but apparently it did need to be 'militarized' to make it more resilient to the elements in a military situation.

But the Remington Model 8 was too complex for a military rifle, and that couldn't be changed by simple modifications. The Wikipedia page for the Meunier states it was partly derived from the Browning long-recoil design of 1900, and it seems to be the case (if the Remington Model 8 is the 1900 design then it has several things in common). So for the French and probably everyone else, a "militarized" Remington Model 8 would essentially be the Meunier A6 rifle- a major redesign to make the whole thing simpler.

 

[Deleted member 1487]

The French were nearly there with the Ribeyrolles 1918.

I read it was a simple blowback rifle.

 

[SwampTiger]

The Ribeyrolles was a simple blowback at 5.1 kg/11 lbs. Would you want to march 20-35 kms/12-21 miles with that on your shoulder? Easier to put a lock or delay in the system, dropping the weight.

 

[phx1138]

Can you get at it "sideways"? Offer a *.22 Spitfire *M1C to USMC, let Army in PTO see how well it works, & have the Army buy it later. Okay, that doesn't get you an *M16 in the '20s or '30s, but...