I ordered 2 Aero uppers 1 last year for the 300BLK build and 1 this year for the 6.5G build. I would have thought they had the same forged marks on them but upon a closer look I see that they are not. Last years has a broken A I guess is Anchor Harvey Aluminum and the recent purchase is M with a diamond Mueller. Interesting find I thought I'd share with the group.