M&P barrel switch?

[KracknCorn]

I want to get a M&P compact in .40, but I want to know if I can switch out the barrel and make it a 9mm?

[puropuro]

I believe you can do a .357sig change...not sure about 9mm.

[Tactical Support]

I want to get a M&P compact in .40, but I want to know if I can switch out the barrel and make it a 9mm?

No you will need to change the complete upper assy and magazine and ejector. Cost prohibative in the 400.00 range in the last quote i got. Also S&W is not in the parts selling business. They would not sell the 40 to 357 sig barrel without installing it.

[puropuro]

Here's an interesting thread if you pursue the .357sig conversion.

http://smith-wessonforum.com/eve/forums/a/tpc/f/520103904/m/6151026013

(basically says conversion is not hard from .40 to .357sig, but finding a barrel may be) The 9mm sounds like a NO-GO.

[Slayer]

9mm and .40 S&W have different head spacing on the M&Ps. You cannot switch to 9mm on any of the higher calibers, only .357 SIG - .40 S&W

[KracknCorn]

I just found a place that offers conversion barrels for the fullsize. http://www.stormlakebarrel.com/barrels. They dont have one for the compact yet... but they say they will soon.

[user5412]

You can convert .40/.357 to 9mm. You're right on with the barrels.

You will need 9mm magazines. You can use .40 mags, but they will not work well.

[Tactical Support]

You can convert .40/.357 to 9mm.
You will need 9mm magazines. You can use .40 mags, but they will not work well.

The head size is different, a 9mm will not function/extract/eject reliably due to lack of extractor engagement. But if you want to sacrifice reliability and performance have at it. I only know this from many years of experience with folks trying to convert Beretta 92/96's.

[railroader]

My buddy has a glock 35 with a lone wolf 9mm conversion barrel. It runs great but I have heard of problems with them. With the storm lake M&P barrel being $175 it sure would suck if it didn't run right. Mark