308 Billet Upper
Short story long I build an AERO M5 during covid with available parts. Recently AR 10 parts production returned to normal so the rifle upper was rebuilt into a long range precision sub .8 MOA consistent rifle. The leftover parts went onto a SOTA 45.00 billet upper for an iron sighted/red dot 20 inch battle rifle with pencil barrel. There is about a .010 gap between the AERO lower and SOTA upper when mated which I chalk up to difference in manufacture preferences. It functions fine and when the front receiver face was lapped the anodizing came off evenly. This indicates square machining, I've seen some where the front face was uneven. This upper does not accept a Breek Arms Warhammer Charging handle, again tolerances, but is fine with a mil spec. The Picatinny is a tad on the tight side but not overly so. For 45 bucks it gets 5 stars. But because of the .010 gap I would not recommend an AERO M5 upper on a SOTA lower, I can see interference there