357SIG - Pros and Cons in a PCC

Flashpoint

Flashpoint

Smile, wait for flash
Charter Member
Supporting Member
Joined
Dec 16, 2016
Messages
3,952
Location
Alamance County
Rating - 100%
21   0   0
I've always wanted a PCC in 357SIG (and 10mm, but that's another thread). The reason being is that I've noticed that in other calibers the lighter weight pistol bullets gained the most out of an extended barrel. I bought my last PCC, a JRC in 40S&W when they were advertising that they had a 357SIG conversion, but when I got around to ordering one they had withdrawn it. Well I recently discovered that the TNW Aero Survival Rifle comes in 357 plus I already knew Mech Tech has a 357 upper as well. The TNW guys are getting approximately 2200fps out of theirs with Doubletap 115gr and 2400fps with some Grizzly 90gr JHP. Standard 125/123gr is coming in just under 2000fps in most cases.

I think this caliber is ideal for a PCC because with it's significantly higher velocity and flatter trajectory it makes better use of the accuracy/stability advantage the carbine gives over a pistol. I loved my JRC in 40S&W, that thing could take deer (never did but I was getting hot 10mm velocities out of it), but I only have one can and its a 9mm so that is another reason why I eventually sold the JRC and am excited to try a PCC in 357SIG. Not subsonic you say? Weill it seems 180gr hardcast 9mm bullets do exist and will work (you can see some in the 2nd video below) so I could load up some subs that would have an energy advantage over 9mm to use in my existing can. What's not to like?

Well, there is one thing not to like. I learned this about a year ago on the Mech Tech forum. The downfall to 357SIG in a PCC is that bottlenecked cases are not a good design for blowback actions. The case begins to move back while the pressure is still high, and it deforms the shoulder. So, once 357SIG brass goes through a blowback gun (like virtually every PCC), it's done. Oh well, won't have to chase my brass I guess.

So what's the consensus, does it sound like it would be worth it to anyone else? Oh BTW, I can buy a 40S&W barrel as well from TNW ($200 I think) and I can switch back and forth in seconds. I still have quite a bit of 40 laying around. :)

https://www.youtube.com/watch?v=_jQTp9LgXiQ

https://www.youtube.com/watch?v=Oxox8r79wI8&t=145s
 
Last edited by a moderator:
Not too much interest in this it seems, lol. I guess most people are thinking a PCC is only for cheap plinking, why not just use a 5.56 if you are concerned about performance, since it is at least as cheap as 357SIG anyway. I get it. The only real answer I have for that beyond the fact that I just enjoy overthinking crap like this and being an oddball, is pistol and carbine ammo compatibility. I also get a charge just thinking of pushing fat (by rifle standards) JHPs to rifle velocities and imagining the mayhem to ensue upon meeting a soft target. I bet it'll blow up fruit (or a critter) better than 5.56.ball!
 
Last edited by a moderator:
I like the idea of .357 Sig in a PCC as a home defense weapon. Sig has promised a .357 barrel (as well as .40) for the MPX. I'm sure the .357 would have far superior ballistics to 9/40. I'm game if the hardware ever materializes.
 
I too think a 357SIG PCC would be very useful. With the additional barrel length you should be able to push the bullet very fast.
 
I am just waiting patiently for Sig to release the .357Sig conversion for their MPX. I hope it isn't vaporware. I love the idea of .357Sig in a PCC. I know it's significantly more expensive, but offers enough benefits to outweigh that for me.
 
There used to be a guy who was a firearms instructor for SHP that shot a 357sig AR at the 2 gun matches at PHA. He let me run a mag through it after a match and it was sweet. Because of the higher pressure cartridge they used a standard buffer in it and it was not as clunky as some of the 9mm AR builds I've shot.

If it wouldn't require having custom machining done I'd be interested in one. I an M&P in 357sig so it's not like I'd be adding another caliber.

One drawback I can think of is having to make sure that the steel at a match is rated for the cartridge.
 
Problem I've heard with 357sig in a PCC is that it is hard on the brass and you might not be able to reload them. It stretches the case when fired, since most PCCs are blowback designs and the bolt starts moving before the pressure has dropped. This would not be a problem with a gas operated gun as the action is locked until the pressure has started to drop.

I just tried to find where I read that, and can't seem to find it now.
 
You must log in or register to reply here.
Back
Top Bottom