Creating the .357 auto

[kawalekm]

Back in the bullet swaging section I was experimenting with using fired .223 cases to make the jackets for .357 bullets. One of the first things I did was use a case mouth expanding stem to enlarge the case mouth to .357". Looking at this expanded case, it reminded me of an enlarged .30 carbine.

Suddenly, my little light bulb came on and I thought of a new cartridge with the same overall silhouette as the .30 carbine but with a straight case measuring 1.76inches long, caliber .327 to .357, that headspaces on the case mouth. This cartridge, which might hold about 30 grains of medium burning rifle powder like H335 might push a 158 grain bullet to about 1900-2000 fps and be adequate for short range deer hunting. It would be fired out of a semi-auto rifle the size and proportions of a mini-14 because it has the same case head as the .223.

Basicly a 13-14 hundred footpound class semi-auto shooting .32 to .357 caliber bullets. Would you buy one?
Michael

[Old Ironsights]

IIRC there are some AR variants that use somthing similar right now...

[EMC45]

Neat idea. You could cut down a .223 case and size accordingly and there you have it. That would feed like a dream I believe.

[wiljen]

Sounds like a rimless 357 Maximum. As I recall Remington makes the 357 max cases from the 2nd draw of 223 brass.

The problem with .357-223 is unless you go with very very thin walls at the neck the nose of the cartridge is gonna be wider than the base.

.223 = .376 base diameter .358 bullet + .013 Wall thickness on average = .384

Be kind of an odd looking bird.

I suspect you are going to wind up basically reproducing the .300 whisper or 30/221 in order to make a cartridge that is both reasonable in dimensions and will fit the magazine. You might look at 8mm or .338 as the maximum reasonable size for the 223 case.

[kawalekm]

The problem with .357-223 is unless you go with very very thin walls at the neck the nose of the cartridge is gonna be wider than the base.

.223 = .376 base diameter .358 bullet + .013 Wall thickness on average = .384



Yes, unless the neck walls are only .010". Alternatively, maybe I could use the 7.62 X 39 as the parent case. The diameter at the shoulder is .394", so if I expanded to hold a .357 bullet the OD of the neck would be just about right. It would still need to headspace off the case mouth, but maybe I could use the mini-30 instead of the mini-14?

[wiljen]

The 7.62x39 to 357 has been done - by the original owners as a matter of fact. Do a quick search on 9x39 and you'll find it was experimented with in AKs amongst others.


Years ago they made a 35x39 they called it the mini-35. You might even find one on Guns America or Gun broker.

I've added scans of the 1993 article in G&A about it to castpics.

http://www.castpics.net/3539/cover.jpg
http://www.castpics.net/3539/350-1.jpg
http://www.castpics.net/3539/350-2.jpg
http://www.castpics.net/3539/350-3.jpg

[leadeye]

I think Wildey chambered a 9mm cartridge like this when they first were introduced back in the 80s. I have always wanted to find a way to chamber the DE for .357 Automag, another high velocity .357.:-D

[C A Plater]

Sound like a new version of the .351 WSL which was one of the inspirations for the .30 carbine. The original rifles were reportedly popular with prisons guards and still show up for sale now and then.

[kawalekm]

Oh thanks. I'll check out my local public library to see if they have G&A issues back that far. I'd love reading about how it performed.
Michael

[wiljen]

Oh thanks. I'll check out my local public library to see if they have G&A issues back that far. I'd love reading about how it performed.
Michael

Just download the files I posted and print em. They'll print full size and are fully legible at that.