I gave in and bought a 350 Legend AR15 upper the other day. My primary interest for this one is subsonic loads (with a suppressor), but I'll also be experimenting with full power loads as well. I will be investigating some of the things we're told we "can't" do on this one - using .357" and even .358" bullets, forming brass from 5.56, etc.

It's good to hear confirmation in the OP that the Winchester brass sucks; I had a suspicion of that. Fortunately I found Starline brass for a pretty similar price.