10-04-2020, 03:56 AM
I have 450 bushy doing same thing , I know mags can b a big problem . Mine is 16 barrel clgs. I checked and double and triple checked everything is correct ! Except the gas port diam . Mine was .0625 that was the issue , to small ! I enlarged it to .076 problem solved . Just put together a 20 rlgs Grendel this week and a 16 Grendel mlgs. Everything between the grendels is identical except the barrels and gas port . Swapped same lower between the 2 and same BCG. 20 runs great , 16 no so . Im pretty confident its gas port size . Will mic the port tomorrow and see what I find .