just finished the .40 upper and the kaw vally gear is nice but kinda slips in alingment.. the barrel nut and hg nut are separate. so you have to use a ( gas tube alingment pin) then torque the barrel.. i find the alingment pin is ok for the gas but not the hg part.. when under tourqe speks. its loose fit in my areo upper.
some slack.. so the finale barrel / hg torqued is to much for the aliingment pin.. minor issues. I run my sights off the upper, not the hg. barrel is snugged tight as well as the md. picked up some glock 22 /22 round mags x4 and have bushell trs25 red dot coming.. fun and games!