The T31 was John Garand’s last project during his employment at Springfield Armory. It was proposed in 1948 as a bullpup configuration rifle to minimize muzzle blast and flash. It was a select-fire rifle with a 20-round detachable box magazine and basically every aspect of the design was unorthodox. The original gas system was more pneumatic than anything else, with the whole handguard tube filling with gas when it cycled. The recoil spring is a clockwork type in the buttstock, and the bolt uses a tilting wedge to lock.
At initial testing it ran into reliability problems after 2300 rounds. Upon disassembly, the found nearly an entire pound of powder fouling in the gas tube. This led to the gun being rebuilt with a tappet type gas system, and that’s the gun we have today to look at. Only two examples were made before Garand retired in 1953, and nobody took over the project when he left.
Thanks to the Springfield Armory National Historic Site for giving me access to this truly unique specimen from their reference collection to film for you! Don’t miss the chance to visit the museum there if you have a day free in Springfield, Massachusetts:
https://www.nps.gov/spar/index.htm
“(…)bullpup configuration rifle to minimize muzzle blast and flash(…)”
Longer barrel will help for that, but would not it be easier to put muzzle device for that. Cones for that should be known to U.S. technical intelligence in 1948 as there were used at Imperial Japanese Army Type 99 machine guns during WW2.
“(…)original gas system was more pneumatic than anything else, with the whole handguard tube filling with gas when it cycled(…)”
This looks to be more complicated variant of one used in Colt Model Potato Digger (with tunnel for gases as opposed to directly actuate mechanism in Potato Digger)
“(…)spring is a clockwork type (…)”
For another fire-arm exploiting this technology see Kretz rifle https://guns.fandom.com/wiki/Kretz_rifle
“(…)fouling in the gas tube(…)”
Another case of Garand assumption w.r.t. ammunition failing. Earlier one was Garand Model 1919 https://guns.fandom.com/wiki/Garand_Model_1919 which relied on maximal strength which primer could sustain.
Knorr Bremse paratroopers rifle next?
The T-31 No. 2 isn’t so much a “design” as a genuine Frankenstein. A heterogeneous collection (I almost want to call it a mish-mash) of bits from other rifles and even light machine guns.
To wit;
1. The bolt-locking system is basically that of the Browning Automatic Rifle.
2. The gas-tappet “short-stroke piston” system is essentially the M1 Carbine’s version, beefed up to handle .300 Savage pressures.
3. The clockwork-spring recoil spring is pretty much straight out of the Lewis Gun. (Well, they also copied the Lewis’ bolt for the FG42, the M60 MG, and the JGSDF Type 62 MG, so all’s fair I guess.)
4. The striker-firing system (because there’s no room for a Garand M1 type hammer in there) seems to have been copied from the German G43/K43 rifle.
As for the original “pneumatic” gas system, I’m not aware of any other design which ever used this sort of setup, even experimentally. It’s not really a variant of the Colt/Marlin-Rockwell system (gas tappet to either a bellcrank or a “straight” gas piston).
It does bear a certain resemblance to the pneumatic cocking systems used on some fixed aircraft machine guns and cannon in WW2.
Beyond that, I got nothin’.
clear ether
eon
https://guns.fandom.com/wiki/T31 provides yet another donor: had the rear sight of a FG 42. as for odd gas system it says following was hoped for
This system was intended to do several beneficial things. First, it would function based on the exit pressure at the muzzle, and not depend on having a particular pressure curve as the bullet moved down the barrel (changes in pressure curves with new ammunition caused the demise of Garand’s first primer-actuated rifle design). Second, it would absolutely delay the action from unlocking until after the bullet had left, thus ensuring safe pressure when extracting spent cases. Finally, the redirecting of much of the muzzle blast would attenuate the concussion of firing, and recoil as well to some extent.
From above it seems as reaction to cartridge with exceptionally high pressure.
Ian keeps bringing us stuff I’ve always wanted to see the insides of, only ever having seen them in books and magazines before. Kudos!
The real “bullpup unicorn” I’d love for him to track down and actually find would be that flippin’ one that they have showing up in late-WWII Manila. Every time I’ve seen something written up about that rifle, I’m left wondering if I’ve just been catfished, so I’d love to know the reality and see what was actually inside the damn thing.
I’ve been hearing about that bastard for years, with no resolution as to whether or not it’s a real thing or someone’s fever dream.
https://forums.spacebattles.com/threads/us-model-45a-americas-forgotten-ww2-bullpup.305621/
I’ve never believed that thing was a working firearm.
But, like you, I’d love to be proven right or wrong.
See the last comment on the old thread. Apparently it was a working firearm. Probably even tested at Aberdeen.
https://youtu.be/Qfe4Y_TBt1w
The barrel seems to be a modified Jhonson rifle barrel. Unfortunately it lacks a picture of the bolt. Piston and op-rod don’t came from the BAR or the Garand, so there had been quite a work on that prototype.
Here’s a thread we had on this critter several years ago;
https://www.forgottenweapons.com/us-model-45a/
My conclusion then and now is that it was a mockup of a potential conversion of the Johnson recoil-operated rifle action to gas operation. The idea being to create a shorter rifle for paratroops that still had the full power of the .30-06 round. In short, an American analogue of FG42.
T31 may have had similar motivation.
Just a guess.
cheers
eon
See the last comment on the old thread. Apparently it was a working firearm. Probably even tested at Aberdeen.
https://youtu.be/Qfe4Y_TBt1w
The barrel seems to be a modified Johnson rifle barrel. Unfortunately it lacks a picture of the bolt. Piston and op-rod don’t came from the BAR or the Garand, so there had been quite a work on that prototype.
The pictures there also clarifies why there isn’t a visible ejection port. Because the thing ejected from the bottom, right behind the magazine. It was already ambidextrous.
The picture of the “receiving block” with the “firing block slot” seems to indicate some sort of frontal rising locking lug action, “a la” Breda PG.
Ain’t no way that that weapon is used for point shooting.
(Scope center-line parallel to barrel center-line)
I’m thinking, on seeing the picture with a rifle-type grenade, that might be for use against tanks or fortified positions!
You can fire a rifle grenade from your shoulder, but your shoulder won’t thank you for it. There was an extra thick slip on recoil pad for the M1 and M1903 that was supposed to protect your shoulder or keep the wood stock from breaking when you braced it against a wall.
There is only a recoil problem if you are shooting full auto?
I’ve shot many thousands of rounds out Garands. No recoil issue in semi auto!
Yep.
Every time you fire a Garand in semiauto from the shoulder, the barrel rises, and shift to the side you are shooting from (on the right, if you are right handed).
Now imagine that, when the barrel is at max height and shift, another shot is fired.
It misses the target, and the barrel rises and shifts further.
Another shot is fired.
At this point, the brain recognises the barrel is rising and shifting, and command the arm to force it down and to the left.
So the next shot hits under and to the left of the target.
And on and on.
https://youtu.be/ch5H6sYnenc
And how did it go with the gas tappet, and what was the problem with that?
That op-rod doesn’t have nearly enough mass, for reliable operation.
I suspect that John Garand had the Art Fry deal at Springfield- no extra money but just work on whatever you want.