I have a M&P40 that I am very happy with, but lately I have been thinking I would like the option of .357Sig. Who is producing and selling barrels for the M&P. I believe the only thing needed for the conversion is a barrel, but I may be wrong. Any help will be appreciated.
I have an M&P .40 and have a factory .357SIG barrel for it. If you want to pay more than the cost of a factory barrel then Storm Lake makes barrels for the M&P as well.
I have a Full Size M&P 357Sig and I ordered a 40S&W barrel from "GunbarrelSupply.com". I know that "Midwayusa" also carries M&P barrels. I put my 40S&W barrel in this morning and went out and ran some Federal 165gr. HST through it, and they were as accurate as I could hope for.