SIGforum.com    Main Page  Hop To Forum Categories  SIG Pistols    Use a P250 .380 Bbl in a P320?
Go
New
Find
Notify
Tools
Reply
  
Use a P250 .380 Bbl in a P320? Login/Join 
Member
posted
I have had a WTB up in classifieds for a while looking for a .380 conversion kit. It looks like no one has one but I just saw something of great interest. Is it possible to run a .380 barrel in a P320? Understand you would need the correct magazine and I am not sure about the RSA. I have found a source for a P250 .380 barrel only. Thanks!
 
Posts: 419 | Location: Northern Virginia | Registered: September 01, 2000Reply With QuoteReport This Post
Member
posted Hide Post
The outside diameter of a .380 barrel (0.471") is smaller than the outside diameter of a 9mm barrel (0.552"), so a slide based on .380 barrel dimensions would be necessary for reliable operation and consistent accuracy.

A .380 recoil spring is markedly thinner and has fewer coils than a 9mm recoil spring.

A .380 slide for a P250 also has lightening cuts that are absent on a 9mm slide, so differences in speed and momentum between the two slides would impair reliability.
 
Posts: 625 | Location: North Carolina | Registered: March 25, 2005Reply With QuoteReport This Post
Member
posted Hide Post
Thanks for the info, sir – I kinda suspected there was a fly in the ointment. There are a couple of places on GB selling “conversion kits“ with just a .380 barrel and magazine. They say it will convert both a P320 and P250 to .380. I should have known that, like too many sellers on GB, they are full of it ... Frown

This message has been edited. Last edited by: GeoJelly,
 
Posts: 419 | Location: Northern Virginia | Registered: September 01, 2000Reply With QuoteReport This Post
Member
posted Hide Post
Sig's factory conversion kits for the P250 and P320 have always included a slide, or more precisely, all parts for a whole gun except the Fire Control Unit.

My guess is the GB ad you saw was made up of parts from CDNN (barrel $20, magazine $10, and grip module $20). The hints that it is not an original factory exchange kit include the lack of a slide and the fact that the grip module does not have a mag release button.
 
Posts: 625 | Location: North Carolina | Registered: March 25, 2005Reply With QuoteReport This Post
Member
posted Hide Post
Last dumb question - will the .40 and .357 barrels work in the 9mm P250 slides? .40 barrels are cheap on GB and I have the ammo and dies ... Thanks!
 
Posts: 419 | Location: Northern Virginia | Registered: September 01, 2000Reply With QuoteReport This Post
Member
posted Hide Post
From a P250 owner on another forum:
quote:
Sorry, no, a 40 (10mm) barrel will never fit a 9mm slide. The barrel extension will never fit the slide breech face.
 
Posts: 625 | Location: North Carolina | Registered: March 25, 2005Reply With QuoteReport This Post
Member
posted Hide Post
So I'm hearing you guys say, it's not a real conversion kit (of course), and that a 380 barrel in a 9mm slide would be unreliable (certainly) and inaccurate, but here's my question: Would it physically work? The P250 parts are so similar. Would it function, even if poorly?
 
Posts: 7 | Location: Kansas City, KS | Registered: June 08, 2019Reply With QuoteReport This Post
Member
posted Hide Post
Bump

Can anyone clarify from actual experience: do the parts fit and function to any degree?

Is that 380 set up just going to perform poorly or is it dangerous/non-functional?
 
Posts: 7 | Location: Kansas City, KS | Registered: June 08, 2019Reply With QuoteReport This Post
Member
posted Hide Post
I would not pull the trigger on such a mishmash of parts to see if it would work.
 
Posts: 625 | Location: North Carolina | Registered: March 25, 2005Reply With QuoteReport This Post
Member
posted Hide Post
Agreed, it seems risky. But I don't know; I wish it would work just for the novelty.

If it's actually dangerous, why are these things advertised and sold with P320 on it?
 
Posts: 7 | Location: Kansas City, KS | Registered: June 08, 2019Reply With QuoteReport This Post
Member
posted Hide Post
quote:
Originally posted by Thumper44:
If it's actually dangerous, why are these things advertised and sold with P320 on it?

To the best of my knowledge, the only top-end parts SIG sold in one caliber claiming they would fit another caliber were .40 S&W and .357SIG.
 
Posts: 625 | Location: North Carolina | Registered: March 25, 2005Reply With QuoteReport This Post
Member
Picture of JBird679
posted Hide Post
The barrel is 20 bucks and the mags are 10 at CDNN. Why don't you just buy one and try it? If I still had my SC slide I'd do it.

You could at least test the lockup and cycling of rounds safely without firing. If it seems promising you could have a gunsmith check things out before firing, or if you like to tinker you could go all MythBusters and set it up in a sled with a string.

Too bad they don't have a Compact .380 barrel for that cheap.
 
Posts: 987 | Location: Upstate, SC | Registered: March 19, 2008Reply With QuoteReport This Post
Member
posted Hide Post
quote:
Originally posted by JBird679:
Too bad they don't have a Compact .380 barrel for that cheap.

SIG did not make a compact-size .380 barrel. The .380 models labelled Compact and Subcompact both used the subcompact-size barrel and slide.
 
Posts: 625 | Location: North Carolina | Registered: March 25, 2005Reply With QuoteReport This Post
Member
posted Hide Post
quote:
Originally posted by JBird679:
Why don't you just buy one and try it?


I think I will. If I do, I'll report it step by step. Also good advice to check with a gunsmith. I know a SIG armorer in my church who could give some guidance also.
 
Posts: 7 | Location: Kansas City, KS | Registered: June 08, 2019Reply With QuoteReport This Post
Member
posted Hide Post
I ordered one of the .380 SC barrels from CDNN and it arrived last week. It fits into my 250 9mm slide perfectly at the chamber end; the barrel hood is a perfect-looking fit with no slop. But, as gc70 mentioned, the barrel diameter is way undersized for the 9mm slide and it is a very sloppy fit at the muzzle. I like the .380 P250 so much I was just hoping to have a P320 in .380 too. Well, at least I have a spare barrel ... Smile
 
Posts: 419 | Location: Northern Virginia | Registered: September 01, 2000Reply With QuoteReport This Post
Member
posted Hide Post
I had forgotten from the OP that the question was about converting a P320, which involves even more issues than it would to put a .380 barrel in a P250 9mm slide.

The P320 is a striker-fired pistol that is cocked when the slide closes. A P320 recoil spring has to be strong enough to pull the slide forward, pick up and chamber a round and cock the striker. At issue is whether a .380 round generates enough recoil to compress a recoil spring that is strong enough to power the return half of the slide cycle.
 
Posts: 625 | Location: North Carolina | Registered: March 25, 2005Reply With QuoteReport This Post
  Powered by Social Strata  
 

SIGforum.com    Main Page  Hop To Forum Categories  SIG Pistols    Use a P250 .380 Bbl in a P320?

© SIGforum 2024