.300 upper - Aero Precision M4E1-T 10in .300 AAC Blackout Complete Upper Receiver

This mounted easily and securely to my Aero lower. I test fired it with a variety of ammo by manufacturer and weight, using a variety of 10 and 20 round .556 magazines (Lancer, Magpul, ProTech). It fired reliably and consistently. I did not really try to zero it because I do not have a scope for it yet (only flip ups) and I was using a variety of ammo. I was pleasantly pleased with the grouping at 50 yards (especially with the heavier ammo). When I get my paperwork, I will SBR, suppress it, and really work on accuracy. As it is right now, I would feel comfortable hog hunting with it. I am looking forward to stretching the limits of what this upper can do with a quality scope and ammunition.