Like you, rage88, my Dad started giving me guns recently and aquired one from my wifes side.
Anyway, I am glad you asked these questions, because I did not know either and asked the guy at Cabelas. He said he runs the cheapest he can find as long as it is not the not-brass russian stuff.
So I just picked up some pmc 9mm luger 115grs. fmj,
so that means the wieght is 115 grams and full metal jacket?
Have not run anything thru my new px4 storm - but this weekend will break it in.
Good luck with your new gun, I do like the M&P and the scale serrations on the slide.