5.7 Johnson and M1 Carbine

[eb in oregon]

A friend asked me to help him complete this conversion on a cheap DCM carbine and I told him that I wanted no part of this project.

Sounds like an excellent decision to me. I wouldn't touch that project with a stick. I've never had the desire to do something "just because." And sticking a cartridge in an M1 carbine receiver with almost twice the case capacity "just because" seems a poor challenge to take up.

[floydthecat]

Sounds like an excellent decision to me. I wouldn't touch that project with a stick. I've never had the desire to do something "just because." And sticking a cartridge in an M1 carbine receiver with almost twice the case capacity "just because" seems a poor challenge to take up.

If one has some old parts lying around, a “just because” fun conversion is 7.62 x 25. You won’t gain any performance or accuracy from it, but you can form your own brass easily enough and shoot Spitzer profile projectiles, or standard .308 carbine projectiles.

[eb in oregon]

If one has some old parts lying around, a “just because” fun conversion is 7.62 x 25. You won’t gain any performance or accuracy from it, but you can form your own brass easily enough and shoot Spitzer profile projectiles, or standard .308 carbine projectiles.

If I can't have a PPSh 41 I see no need to make a carbine in 7.62x25 as .30 carbine is superior in all loadings and I don't like tweaking magazines or feed ramps. I was fortunate once to have an article published in Handloader magazine (issue 201 Oct 1999) so I'm very familiar with the cartridge. And even though I've still got bunches of it, with a few hundred formed from 5.56 (when I first started working with the cartridge there was no boxer primed brass available and though I've done it I avoid berdan primed). Like I mentioned, "just because" doesn't float my boat much. I've enough to keep me occupied already.

However if a guy want's to do such a project that's all well and good. But the 7.62x33 mm Kurz in a M1 carbine doesn't sit well with me. I've seen rifles chambered in cartridges the receiver wasn't designed to hold. It may work for a while, but eventually it will blow up. I've seen it and applied first aid.

[browningautorifle]

a few hundred formed from 5.56

That's an interesting side note. I never thought about making 7.62x25 from 5.56 brass... We still have far more steel around although most ammo is harder to find now.

[DaveHH]

That caliber has a reputation of being a killer but if you read Korean war books like "Break Out" or SLAM's "River and the Gauntlet" there were a lot of Marines getting shot with a PPSH 41 and keep right on fighting for hours and days.
The bullet is really light if I'm not mistaken. The commies used their 7.62XX25 to give people "9mm headaches". If I had a choice between a MP38/40 or a PPSH, it would be a hard choice. I'd probably go for 71 rounds instead of 30/40.

[eb in oregon]

That caliber has a reputation of being a killer but if you read Korean war books like "Break Out" or SLAM's "River and the Gauntlet" there were a lot of Marines getting shot with a PPSH 41 and keep right on fighting for hours and days.
The bullet is really light if I'm not mistaken. The commies used their 7.62XX25 to give people "9mm headaches". If I had a choice between a MP38/40 or a PPSH, it would be a hard choice. I'd probably go for 71 rounds instead of 30/40.

There is a difference between one hole or five or more. The PPSh 41 is a remarkably easy gun to hold down for accurate fire on automatic fire. And with a fire rate of more than double the MP 38/40 (about 1250 or so vs 500) with less recoil it's not something to dismiss because the loading was only a 85 grain projectile at about 1600 fps.

[floydthecat]

That's an interesting side note. I never thought about making 7.62x25 from 5.56 brass... We still have far more steel around although most ammo is harder to find now.

Nothing to it. The TOK sizing die easily creates the shoulder. I use .223, 5.56 and 300AAC brass.

[browningautorifle]

I use .223, 5.56 and 300AAC brass.

With some inside case neck reaming I would suspect? I made about 600 rds of 7.92 Kurz decades ago for a man with an MP44 and used Federal once fired .308. Had all the toys to work with including the inside case neck ream...

[eb in oregon]

Nothing to it. The TOK sizing die easily creates the shoulder. I use .223, 5.56 and 300AAC brass.

As mentioned when I first started working with 7.62x25 there was no new commercial boxer primed brass available that didn't include buying really expensive commercial ammunition so I formed two hundred from 5.56 brass. First shortened, then formed, inside neck reamed, resized again, then trimmed to length. A lot of work. Then about eight months later Starline started making brass and I bought a few hundred more. Much easier. While there is "nothing to it" it is labor intensive and I see no reason to make something I can buy readily. I only make stuff I can't find anywhere else (such as 5.7MMJ) as then you can spend more time shooting it than making it. I try to save the "making" part for absolute need.

Edit: It's labor intensive enough that I'd put up a large tarp to catch the brass as a CZ 52 launches cases like an Olympic javelin thrower. Losing a few cases was almost physically painful after all that work.

[floydthecat]

With some inside case neck reaming I would suspect? I made about 600 rds of 7.92 Kurz decades ago for a man with an MP44 and used Federal once fired .308. Had all the toys to work with including the inside case neck ream...

After I size, I hit the mouth with a 19/64 drill bit, but anything close to .300 works. It has to be cleaned up a tad before it can be flared or the flaring die might hang-up on the mouth edge. I don’t flare much at all, just enough to start the bullet.