I have a complete M5 .308 18” upper from Aero Precision and have shot it several different occasions and had issues with it short stroking, weak ejection patterns (if it does eject), and failure to eject. I have a M5 Carbine length lower on this build that I bought from Aero as well. What could be causing these issues? The most I’ve ever had it work was 5 rounds after the bolt carrier group was drenched in gun lube. I’m at a loss here as it is my deer rifle this season and I’m not sure what else to do to try to correct this problem. Please help.