9 mm or .357 Sig barrels for the Sigma SW40V

libertasdon · #1 05-03-2015, 01:17 AM

I was wondering if there are 9 mm or .357 Sig barrels that will fit the Sigma SW40V. I have a Sigma, but I am a revolver guy mostly, so after I bought the Sigma in 1994, I just put it away and forgot about it. Now, if I do not sell it, I think I might put together a conversion package for either 9 mm or .357 Sig, or both.

I imagine some fitting and possibly new slide springs are required. Will the .40 cal Sigma magazines hold and chamber .357 Sig ammo with little or no modification? Any 9 mm mags that fit the 40 out of the box, so to speak?

I am also considering an upgrade in sights -- maybe an electronic dot, like an Aimpoint, or possibly just a front night sight.

I would be very appreciative to hear what anyone has to say who has some prior experience on the subject.

colt_saa · #2 05-03-2015, 01:44 AM

357SIG and 40S&W share magazines and recoil springs in all firearms.

Factory 357SIGma barrels are almost impossible to find. 1500 were produced and most went to firearm production.

I acquired one of the extra barrels a while back with the intent of using it in my SW40F. What I forgot was that the SW40F and the SW357V were different barrel lengths

I ended up finding a few original SW357V pistols and the barrel was sold to one of our Forum members last year.

In terms of shooting 9MM with your existing 40 caliber SIGMA, you will have to buy a conversion barrel from one of the aftermarket companies. Factory 9MM mags work just fine in your frame. You will also need a replacement recoil spring for 100% reliability, the 40 caliber spring will work with some or most 9MM ammunition

libertasdon · #3 05-03-2015, 03:31 PM

Colt SAA,

Thank you for the very informative post. Looks like you have been there and done that already.

OKFC05 · #4 05-03-2015, 04:16 PM

The SIGMA 9mm magazines and mag wells are more narrow than the .40 SIGMA mags and magwells. I have both, and they do not interchange. There are no currently manufactured .40 to 9mm SIGMA barrels. The 9mm mags are loose in a .40 frame.
I have seen 9mm barrels put in a .40 and used with .40 mags and 9mm ammunition. It didn't blow up, but it was not what you could call reliable.

The M&P mags and magwells are the same width between 9mm and .40 calibers, but not the SIGMAS. The SIGMA .40 and .357 magazines are the same magazine.