re: Official AR-15 thread

Have any of you ever had feed ramp problems from a brand new ar? I have pretty much narrowed it down to this issue, however I have never personally had any problems with this. My dad bought an m&p 15 today and it shoots and ejects fine when a round is force charged into the chamber, but has issues picking ammo off the magazine. It came with a pmag, and I have used several of mine on it along with different types of ammo. I have polished m4 ramps on mine and have never had this issue. Any suggestions aside from calling s&w and shipping the upper back to them. He is just getting into black rifles and is discouraged now to say the least, but rightfully so. I'd be pissed.Eta: I stripped it down, cleaned it well, focusing a lot of detail towards the chamber.