M1 Carbine in an intermediate caliber

[floydthecat]

The biggest problem with most of the many cartridge variants that M1 carbines had been converted to over the years, was finding one that actually provided a ballistic advantage over the .30 carbine round while confined to the Carbines 40,000 cup max operating pressure. Very few cartridges performed better within this limitation when compared to the M1 Carbines original performance requirements.

This...this is the main reason along with action length that it seems futile to try and make the 7.62x33 something better. However, you can convert to the .355 family of pistol cartridges. You won't gain any performance over the 7.62 x33, but from an 18-inch barrel at ranges out to 100-yards....the 9x19 will do anything the 7.62x33 will do. All you need is a barrel and they are available at reasonable cost. Some light machining is required on the piston, nut, and bolt-face, but it remains a 100% gas-operated USGI carbine. Marlin and Ruger make a pretty good camp carbine, but lug one around all day and you will appreciate the feeling of packing something more closely related to a 10/22.

[RCS]

I always wonder if US Ordnance gave any thought to the Winchester 35 Self loading Cartridge for the carbine, they did use the smaller brother, the 32 WSL cartridge. With a 150 gr bullet these fit right into a carbine magazine. this 35 WSL is nothing more than a rimless 38 special case (like the 38 AMU pistol cartridge) plus you can still get a good velocity with a heavy 35 cal bullet

[floydthecat]

Not sure what pressures are generated by the 35WSL. 35,000 psi is about the bottom end of what is needed for cycling and the 9mm barely meets that.

Heavy 9mm slugs in the 145-grain range actually cycle better than 115-grain loads.

Rimless .357 magnum would likely run, which would almost be a 9mm magnum that does run well in conversions.

[lboos]

delete.

[eb in oregon]

I always wonder if US Ordnance gave any thought to the Winchester 35 Self loading Cartridge for the carbine, they did use the smaller brother, the 32 WSL cartridge. With a 150 gr bullet these fit right into a carbine magazine. this 35 WSL is nothing more than a rimless 38 special case (like the 38 AMU pistol cartridge) plus you can still get a good velocity with a heavy 35 cal bulletAttachment 122613

So we had 30.06 and .45ACP as standard infantry calibers. You really think it beneficial to adopt a third completely different caliber along with the related tooling required during a time of war?

[floydthecat]

So we had 30.06 and .45ACP as standard infantry calibers. You really think it beneficial to adopt a third caliber along with the related tooling required during a time of war?

That was a common string of thought and I understand the .276 was shot down for that reason, but they went against that thought of caliber commonality when they chose the 7.62x33 round for the carbine anyway……a third caliber.

[eb in oregon]

That was a common string of thought and I understand the .276 was shot down for that reason, but they went against that thought of caliber commonality when they chose the 7.62x33 round for the carbine anyway……a third caliber.

A third cartridge, not a third caliber and diameter. When the specifications for a new Carbine were released for development .30 caliber was specifically required due to the issues of tooling and some commonality. McArthur personally "shot down" the .276 specifically due to the millions of 30.06 already in inventory.

[mrclark303]

Hi all, I just wanted to thank everyone for their input in this thread. It's opened a whole new world of wildcat cartridges for me to study!

[floydthecat]

I luv the little gun for what it is, not because it shoots 7.62x33. Several other calibers are available for conversion that will not seriously alter the action. 30-carbine at a dollar a round might be reason enough to seek an alternative.

[eb in oregon]

Merely an opinion, but if a person want's to "poop up" a .30 Carbine they are better going down in diameter than a larger diameter. 5.7MMJ does very well out to 250 yards, requires little alteration of the original rifle, and delivers a 40 grain projectile at 2800 to 3000 fps. It is far superior to 5.7x28, though not hardly a pistol cartridge of any sort.

http://johnsonautomatics.com/message...bd5072a985.JPG