I know it's probably been asked before, so please forgive my inability to do the search. I'm lazy like that!

Can I use a S&W Factory 9mm barrel and 9mm mags in my M&P 40's slide without any issues? Or is there a big difference between the size/outside diameter of the 9mm barrel vs the 40?

I know Storm Lake makes their conversion barrels, but they're never in stock and kind of pricey. I would also like to stick with S&W parts if possible.

Thanks in advance, and feel free to beat me with a big stick for asking something that's probably very redundant.