.357 barrel

[Backon4]

I remember seeing where someone was modding a 9mm barrel to accept 357sig. I can't seem to find it and wanted to know how it turned out. If you see this post up because I'm really interested.

 

[OKFC05]

I followed the posts closely, but I'm not the one that did it.
By using a chamber reamer, he carefully chambered a factory Sigma 9mm barrel and fitted it to a .40 gun. The .40 gun is necessary because of the magazine being the same for the .357, as well as the extractor.
He said it took about 4 hours work, but it did function. The conversion does not work in a 9mm gun, since the magazines won't interchange.

For an M&P, the solution is much easier: just buy the factory .357 barrel and put it in a .40.