Excellent upper - Primary Weapons Systems MK109 MOD 2-M, .300 AAC Blackout, 9.75 inch Upper Receiver

Purchased this upper to build a truck gun. The size is perfect and very quiet with a Nomad can on it 220g subsonics. Shot very well with noticeable reduction in gas. I would definitely purchase this again and will probably get their 223 wydle for my next build. Very good quality and runs great with my COLT lower, BCM charging handle and a laRue trigger. Fit was mil spec. I did have to rezero my Credo about 10 clicks to the right compared to my 556 just keep that in mind. Also, with this size and twist rate the upper is best suited for subsonic 220g. That's exactly what I wanted. Short and very quiet.