Could 5.7 Johnson have been more successful w. more-modern powders, better reloading

steelgray

steelgray

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Ah yes, in the early '60s, Melvin Johnson came-up with (or advanced) a pretty good-sounding idea. Neck down the 30 carbine brass to .224 and re-barrel existing carbines to shoot a flat-flying 22/ 30 carbine round - 5.7 Johnson A.K.A. 22 spifire.

He sold conversion kits with brass and reloading data see https://www.billstclair.com/weaponsman.com/index.html%3Fp=32990. Someone else (IAI American Legend) seems to have produced and sold complete M1 Carbines in 5.7 Johnson spitfire see http://www.m1carbinesinc.com/carbine_iai2.html.

When one considers the more recent interest in PDW cartridges - and guns in 5.7x28 and 4.8x30 bore, you have to wonder if Mel was ahead of his time. And now that Justin wants to block future transfers of restricteds, it's a better-than-average time to re-barrel your M1 Carbine to non-restricted.

Why not do a custom barrel conversion to 5.7 Johnson A.K.A. 22 spifire? Works for me. But why wasn't the cartridge a better performer, back in the '60's and '70's - when it was in-play? Why was the 5.7 Johnson only producing 750FPE versus 960 FPE of energy for the .30 carbine original.

Could 5.7 Johnson have been more successful with more modern powders, and/ or better reloading methods?
 
Modest operating pressure stops the round from really shining. It's a cartridge I had a strong interest in but never got around to playing with. The modern PDW cartridges have very high max pressure limits which help them squeeze as much performance as you reasonably can out of the small cases.
 
I have a friend with a 17peewee build on a mini mauser action.

Its an awesome little round. The 223 is probably better in every way over anything made with a 30 carbine case.

Unless its for a very short action semi that couldnt handle the 223 length.
 
That's the point. You can't shoehorn a 223 win into an M1 carbine. 5.7 Johnson fits but, IMO, underperforms. Could that have been solved if people in the day had access to modern reloading powders and components or if they had just done a better job cooking up loads?

Evanguy said:
I have a friend with a 17peewee build on a mini mauser action.

Its an awesome little round. The 223 is probably better in every way over anything made with a 30 carbine case.

Unless its for a very short action semi that couldnt handle the 223 length.
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steelgray said:
That's the point. You can't shoehorn a 223 win into an M1 carbine. 5.7 Johnson fits but, IMO, underperforms. Could that have been solved if people in the day had access to modern reloading powders and components or if they had just done a better job cooking up loads?
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The performance today isn't any better than back then. I don't mean to sound rude but isn't the answer a bit obvious? As I mentioned the operating pressure is fairly low. It's not exceptionally high compared to many pistol cartridges let alone rifle cartridges. Small bore low(ish) pressure cartridges can only do so much.
 
I say the biggest set back was the parent cartridge & rifle. Seeing how except for some odd balls, only the m1 was chambered for the 30carbine & the johnson, the abundance of 30carbine surplus ammo left very little demand for a 22 wildcat variant back in the day.
The 22tcm & FN's 5.7 obviously shows today that the idea wasn't a bad one, but they are still not a widely popular offering in anything but niche(not the right word but best I can think of) firearms.
 
As a kid, I knew a fellow who had a couple of those rounds. I remember putting one back on the dash of his truck, and watching it roll into the defroster vent. I seem to recall seeing Numrich listed replacement barrels in their catalogues.

It is a dinky little cartridge no matter what you think about it's superior abilities. Other than make bang sounds and hit paper, it doesn't have much else going for it.
 
maple_leaf_eh said:
As a kid, I knew a fellow who had a couple of those rounds. I remember putting one back on the dash of his truck, and watching it roll into the defroster vent. I seem to recall seeing Numrich listed replacement barrels in their catalogues.

It is a dinky little cartridge no matter what you think about it's superior abilities. Other than make bang sounds and hit paper, it doesn't have much else going for it.
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That depends on what you're hunting. I shot a lot of rabbits, marmots, ravens (that liked to kill and eat the new chicks) and several coyotes with that diminutive cartridge out of a converted M1 Carbine.

Worked great for shooting pigs during slaughter time as well.
 
bearhunter said:
That depends on what you're hunting. I shot a lot of rabbits, marmots, ravens (that liked to kill and eat the new chicks) and several coyotes with that diminutive cartridge out of a converted M1 Carbine.

Worked great for shooting pigs during slaughter time as well.
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Friend of mine had one in the 70's, and I had a regular M1 carbine. We shot small game up to wolves with them. Neither were great game rifles, but they were fun, light, and did the job. And you didn't care much if it got banged up strapped to the side of the snow machine. - dan
 
I've thought of converting an M1 carbine to 5.7x28. It looks straightforward. An original 15 round mag with spacers would probably work and the bolt face wouldn't need much adjusting - if any. I'd reline and rechamber or replace the original barrel (maybe to 18.6 inches). The 5.7x28 round is smaller (in terms of case capacity) but works at a higher pressure so I'd use the stock gassing set-up and see how it ran.
 
Thinking back 40-50 years. The rifles were cheap, and surplus ammo cheap and available. Think to a decade ago, the SKS, at then prices for rifle and ammo. Converting to a different caliber would cost 4x the original purchase price, who would do that?

The design of the M1 carbine is just not taking a high performance upgrade, simply not designed for it. It was a secondary level troop improvement on a 1911 45acp handgun. Think truck drivers, cooks, or corpsmen. Cheap to produce, good to 100yds, minute of Japanese soldier at that distance.

A simpler, cheaper, more practical solution would be soft point hunting ammo in 30 carbine, at surplus prices. Perhaps reloading projectile in soft point.

I've played around with 7.62x39, and 6.8 spc for the little blacktail here. Really though it's a solution for a question Noone is asking. There are some solutions , ultimately probably cheaper than a expensive conversion on a almost worthless gun, a 243 win Browning bar off the top of my head.
 
I would be cautious about trying to convert an M1 Carbine, the are not cheap anymore

Now an SKS, that looks like an option, just neck a x39 case to 5.45mm

I dont think the Chinese 5.8x42 would be viable but a wildcat 5.8x39 might work
 
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