I have a boat load of .357 Sig ammo from work and was thinking about converting a 40 or 10. It seems like a simple swap of the barrel, magazine and possibly recoil spring. Has anyone done this with success? Any problems?
As you said, you'd need to start with a .40 or a 10mm, other than that, I can't imagine any issues.
I was commisioned to build one a year ago. The hardest part was figuring out what recoil spring to use. I used .40 mags with extra power springs. You also need to go heavy on the recoil weight. After working those bugs out, the gun ran flawlessly.
One of the better smiths here can probably chime in and give you more, but that was my experience with it.
I have a .40 springer that I bought for shooting matches with, A buddy who is a LEO in another town had his dept switch back to 40 after trying .357 sig and they had scads of ammo, so I did what you are looking at.
My choice was a bar sto barrel, I used a 24 pound recoil spring, and for the american eagle FMJ stuff we had, it was perfect. regular .40 S&W mags fed fine. Only real issue I had was it was eating shok buffs, I added a square bottom EGW firing pin stop to slow the opening and that worked perfectly. I probably shot 4000 rounds this summer with no issues at all.
I have a Burns Custom 10mm that I am thinking about converting to .357 and I want to be able to switch back and forth easily. Would 10mm mags work okay or is there a better recommendation?
The 10mm mags might feed fine, and they might not. The gun will tell you what it likes. If it doesn't like 10mm mags, then 40s will do the job.
I am on the home stretch with one right now and it's been problematic but not so much because of the caliber-- just a bunch of other little things. The customer sent a bunch of components and some of them weren't quite right for the application, like the slide stop was for .45, stuff like that.
I'm using Tripp mags for .40 S&W. As far as feeding and cycling, no problems that could not be surmounted. But it has a compensator and is really, really loud. Gunfighting in the back of a taxi is definitely out with this one.