Couple of things to check. Was the bulge at the base or where the bottom of the bullet is in the case? Kind of hard to believe a bulge in a 9mm that won't feed in an M&P chamber. I'm still guessing crimp.
Is your sizing die literally just kissing the shell plate? It has to be real close if not touching to get the most sizing.
What brand of die? If it's Dillon it will rarely get low enough on the case to size it all.
Are you sure they are not too long? Will they spin in the chamber?
Crimp should be in the neighborhood of .376-.379.
Dillon Dies. So.... After reading the genius on this forum, I adjusted crimp, same issue. Looked at sizing die, everything was good, so I went and ahead and adjusted all the way down, and what do you know? Walla. The RP's will spin freely in the barrel.
I still feel a slight bulge, but the "bulge" is way closer to the head than prior. I guess only the RP was sensitive. I don't feel so bright, only 10 shells to re-work. Guys, I appreciate all the help.
I am still in the beginning stages of reloading (<10000), but this forum has increased my knowledge greatly.