5.7MM M1 Carbine Questions

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carbine85

carbine85

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I'm toying around with the idea of building my next M1 Carbine in the 5.7MM Johnson.
Do any of you guys have one or have any experience with one?
How good is the accuracy? I know it's better then the .30 carbine.
Seems like it would make a nice project gun and making my own wildcat rounds would be fun.
 
Sounds like an interesting concept. I read up on it here:

http://www.reloadbench.com/cartridges/wmmj57mm.html

When you first posted it, I thought you were talking about an M1 carbine converted to 5.7x28mm, which piqued my interest. From the ballistics info, it looks like the 5.7 Johnson is just a tad hotter than the 5.7x28?

Either way, it looks like it would be a neat gun, very flat shooting. It also seems to me that if the new barrel has the same OD as the original .30 carbine barrel but the smaller .22 bore, the new barrel might be a little heavier and stiffer than the original GI model. I'd think that accuracy would improve, and it would definitely be flatter shooting.
 
It looks to be much hotter than the 5.7x28 (about twice the energy from an FN P90), but availability looks to be, well... nonexistent?
Keep up updated as it sounds interesting!
 
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I think it was only ever available as a home-cooked wildcat, and the development of .223 kind of guaranteed its obscurity -- but it's a cool idea, and I'd also be real interested to hear how one runs and how the round performs.
 
5.7mm Johnson? Viagra can help, Viagra has been helping Men with 5.7mm Johnson's for a very long time, talk with your doctor today to see if Viagra is right for you!
 
This was a kind of sort of common conversion (as conversions go) in the 60s, but I think problems with ammo availability and reloading did it in. I have a whole bunch of the brass I've picked up over the years, and thought about converting one of my carbines (briefly, very briefly), but after reading up on it determined that brass issues made reloading problematic, and brass life rude, brutish and short. Ballistics were pretty good, around 2800 fps for a 40-50 gr slug in a carbine length barrel, which is what caught my attention but my ARs made it unnecessary, so I lost interest. :cool:

Here's some poop from the The Reloading Bench:

http://www.reloadbench.com/cartridges/wmmj57mm.html
 
A fun cartridge, but the idea of having to convert the brass and then have the gun spit the fruit all that labor into the bushes was always a turn off, not to mention the cost of the dies.

Buy a Mini-14 instead.
 
I've only seen one and read about several more. Case life is not a strong point. A friend bought one of the Israeli ones (IAI?). The difference in location of the shoulder in a fired case vs. the unfired was easily seen. The other aspect of case life was it's trajectory after firing. This particular one would shade an H&K91. Dies are very expensive, and his first set was defective.
It was fun to shoot and he was getting 2900 with 40 grain bullets. And it was lighter than the original M-16's.
 
I have rebuilt and built M1 Carbines. I finished a parts guns about 2 years ago. If I can pick up a commercial M1 I would just replace the barrel or find a receiver and build it from the parts I have.
The ammo shouldn't be a problem since I can make my own cases from .30 carbine brass.
I have seen the commercial built 5.7's sell for $700-$800
 
I love M1 Carbines, but somehow I don't care for any of the wildcats, heck I would rather see other carbines chambered for .30M1 (like the FN PS90) rather than the M1 Carbine chambered for something else, but as long as it doesn't compromise the handling of the carbine (and it doesn't) I don't see how it could be all that bad. I think the 5.7mmJohn is the most common wildcat for the M1 Carbine, so there should be some pretty decent loading information out there, and it uses the same brass so that won't be an issue. Also, .30M1 is relatively expensive so you just about have to reload for it anyway. If it appeals to you I'd give it a shot.

:)
 
I would rather see other carbines chambered for .30M1 (like the FN PS90)
Click to expand...

:D Yes! Shamefully I haven't thought of this myself as it sounds like a lovely idea! I question the strength of the P90's (blowback) action of the .30 Carbine that lobs a bullet nearly 3 times the weight (40 vs 110), but I don't see why it can't be at least tried by increasing the recoil spring tension.

Yes, I would buy a PS90 if chambered for the .30 carbine for the obnoxious price PS90s are going for these days, especially if they were able to keep the magazine capacity as close to 50 rounds as possible (assuming the 7.62x33's case diameter is only slightly larger than the 5.7x28's).

This Google images indicates cartridge OAL might be a magazine concern though.
4.6x30mm,_5.7x28mm,_.30_M1_Carbine.jpg

Great, yet another would-be firearm to dream about.

Sorry Carbine85 for the off-topic content, I don't mean to hijack.
 
Yes, I would buy a PS90 if chambered for the .30 carbine for the obnoxious price PS90s are going for these days
Click to expand...
FN, can you read this...now there is two of us...please make one.

...cartridge OAL might be a magazine concern though.
Click to expand...
I doubt it...there is only about 1/100th of an inch difference in COAL (according to SAAMI), so unless they make the mags way too tight it should fit (as far as length). I would surmise that the capacity would be reduced to 30-40rnds, but I can live with that. I think the added power of the cartridge would be a concern, but it is about on par with a .357Mag. so I don't think it is something that couldn't be overcome.

...now back to the 5.7mmJohn M1 Carbine...

:)
 
Hey guys, please bear with a newbie on the forum. I have two M1 carbines that I inherited from my father when he passed away. I am interested in converting one of them to 5.7X28mm but don't know where/how to start. Any information would be appreciated.
 
What I'm finding is the barrels are $200 more or less, the brass forming and reloading dies go for another $200-225. RCBS told me 3 months to get the dies. I found a new barrel but no way to head space it. Unless I find some good deals I'm dumping the idea and just build another carbine.
The Iver Johnson Carbine parts I have to build off are a P.O.S. compared to the USGI. If you have USGI Carbines I would leave them the way they are and find something else to build on.
 
That's an interesting build and I just recently saw a barrel for sale. Might have been on GB. I agree about keeping the GI carbines original even if they were not matching numbers.

On a side note, I've been intrigued by the 30 carbine round for a while. It seems there is little discrepency in load data as far as bullet weight/style and power. Is that because of the cartridge or the gun design ? I always thought the 30 carbine round would be nice in an AR instead of a pistol caliber.
 
I think I remember seeing someone was making a 30 Carbine upper for ARs, with some sort of adaptor block to use standard carbine mags with it. Haven't seen ads for them in a few years, though, so it may have just been vaporware or a real low volume seller.
 
I have the forming dies and reamer for the 5.7 Johnson, I made a rifle from an IMI barrel several years back and use carbine brass formed works well if you keep the pressure low... 12 grains of 4227 seems to give me speed and keeps the pressue low... but I started out at 11.5 and that also smoked! If anyone is interested... get a barrel and have it installed... I have the head space gages and reamers you can borrow. You can get Redding dies and your ready. As for brass, I can make you a thousand rounds of brass if you want... we can talk about price if your interested... I like the little thing.
 
What modifications were made to the M1 carbine to make it fire 5.7 Johnson? Since the 30 carbine rifle was the parent I assume the gasport hold was probably smaller. Anyone have the Saami specs for 5.7 Johnson? Id like to know how it compares to the FN 5.7 but I suppose I can look at .30 carbine for case head information ect.
 
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