Why no .357 sig rifle/carbines?

.223 is likely to go through and through at short ranges where the pistol round is going to dump all of its energy inside the target.


I disagree. The .223 is more likely to fragment or expand at close range than it is at long range. In military FMJ loads, pistol caliber rounds are unlikely to do anything but poke a small hole as it passes through the target while 5.56 FMJ might fragment and dump all its energy.
 
There is a very good argument to be made for the .357 in a carbine, from a performance/cost perspective, IF you handload.

Not.

First, the .357 Sig cartridge case is based on the .40 S&W and uses a 9mm (.355") bullet. .40 S&W cases are as plentiful as dirt at most shooting ranges and are also easy/cheap to buy. 9mm bullets are in every handloading catalog and store that carries loading supplies.

From a cost standpoint, 55gr FMJ component bullets are cheaper than jacketed 9mm of any weight. Lead and copper are expensive. Twice as much or more are needed to make the .355 pistol bullets.

When necked down to .357 Sig, the .40 S&W case ends up a hair shorter than a factory .357 Sig case. Normally, straight-walled, auto handgun cartridges (9mm, 40 S&W, 10mm, .45acp, etc.) headspace on the case mouth and brass that is too short tends to be inaccurate. HOWEVER, since the .357 Sig headspaces on the shoulder (and not the case mouth), this creates no problems.

The .357 SIG headspaces on the case mouth. That is what my Speer #13 says, and a couple other manuals, too ...... Not only will the headspace be wrong, but making the already short neck even shorter will not leave a whole lot to grip the bullet .... PARTICULARLY if you use the shorter bullets (you stated cost was a factor, and shorter=lighter=cheaper): the ogive (curved portion of the bullet) begins sooner ..... not much area for gripping the bullet is a recipe for bullet set-back, and bullet set-back in a tiny cased high pressure round like the SIG can make for an exciting trip to Splodeyville: Ka-Boom!

There's a reason there are none out there: It's a dumb idea with no upside, and lotsa liability issues waiting to happen.....
 
Some published info on reloading .40 Smith brass to .357 Sig:

"The .357 SIG headspace is determined by the shoulder, not the case mouth, just like the .400 Cor-Bon and virtually every other rimless or rebated rim bottle neck cartridge. Probably why people have frequently and successfully used necked down .40 S&W brass to make .357 SIG cases, even though the .40 S&W is over .020" shorter."

http://www.realguns.com/archives/001.htm

And:

http://www.realguns.com/archives/112.htm
 
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If I was going for a Semiautomatics Pistol Caliber Carbine it would be a 50AE.

I really dont see the reason for a 357 sig over a 357 magnum if they where both semiautomatics (like the Desert Eagle).
 
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