I got my S&W M&P in the other day and it works great. But for future reference I'd like to know if if it's possible to change the caliber up (I know you can convert any to 22, just not sure if the opposite is true). I want to convert it to something above 5.56, but not to a full sniper round, so if you have any suggestions. Also I saw a titanium receiver and I was wondering if I could switch them out. Thanks.