Hello. I'm considerably new to this forum. So Far I Have Found A plethora Of Information And I Greatly Appreciate It. Now For My Question. I'm Considering Buying A .357 Sig Barrel For My M&P .40. I've Seen Some YouTube Videos But No One Has Said If The Frame And Recoil Springs Are Taking On Any Extra Wear. I Really Like The Idea Of Having Multiple Barrels For One Weapon But I Don't Want To Do It At The Cost Of My Favorite Firearm. Thanks In Advance For Any And All Help And Opinions. Sorry About The Caps My PhoneDoesn't Like This Format And I'm Not Paying For Tapatalk.
M&P .40 to .357 sig
- Thread starter AWAtS
- Start date
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to the best of my knowledge, the stock 357 sig barrel can drop right into the 40 with no other changes. I bought the barrel but don't have any sig ammo so i've never shot it in that configuration. I also have the stock 9mm barrel but don't have any magazines to test that out either.
Rastoff
US Veteran
As I understand it the frame is the same for 9mm, .40S&W and .357SIG. So, you won't damage the frame by shooting the other calibers.
tectrry
Member
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- Apr 30, 2013
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I shoot more 9mm ammo through my .40 with the stock 9mm barrel dropped in than I do .40 ammo without any problem. Have not put the .357 barrel in but I understand that all of the parts are the same (recoil spring, etc.) and shouldn't cause any problems.
Wee Hooker
Member
FWIW, I have a 357 sig match barrel for my 40 pro. I've not seen any downside to running this caliber but admittedly have only run a few hundred factory 357 sig rounds through it. Most of my 357 sig shooting is with my own reloads which are closer to 9mm than 357sig in velocity.
chuck perry
Member
Dave, who did your match 357SIG bbl? I'm watching and waiting for a good deal on a used 5" M&P 40 to convert to 357SIG, wonder if you had any issues with your bbl?
Both the .357 Sig and the .40 S&W are high pressure rounds producing about the same pressures in either caliber depending on the exact load you are using. You will not hurt your gun with either caliber, if you want you can replace the recoil spring up a notch or so from Wolf. I do that anyway as I tend to shoot high pressure loads, it is like chicken soup, it can't hurt. Unless you use wimp loads with the stronger spring, I would just leave it be and change out recoil springs at the builders recommended intervals.
