Hey guys, so I know that Sig does this, but I'm about to purchase the m&p 9mm, until I read a post in a thread about a guy about to buy a m&p 40 and purchase a 9mm barrel to go with it so he can have both calibers.

I haven't gotten a response from him yet so I'm asking y'all if you know about it or have this setup and it's PRO's and CON's.

Thanks guys...