I just fired my grendel upper for the first time yesterday. 90% of the time it has a failure to feed, 10% fte. When it ejects it is really weak maybe 3 o clock 6". It did this with wolf and hornady black ammo. The lower is borrowed from my 300 bo and I know it's good. The upper is an aero reciever, psa full auto bcg with supplied bca bolt, the barrel is a 20" bca heavy contour, gas block is anderson low pro .750. Last round holds open on bolt body or mag, not sure as I was pissed off but the bolt was beyond the mag follower.
I have to assume it's short stroking due to low gas. Admittedly I did not measure the gas block hole placement to barrel hole as the barrel was dimpled, could the dimple be off for the anderson low pro? I'm in the mountains hunting so I can't take it apart to check until I get home. Just looking for some experience with the block dimple being wrong for the anderson. Or something I over looked. Brass was good after firing, don't believe it's a mag issue, bcg, buffer or spring issue. I'm kinda leaning toward too little gas.
I have to assume it's short stroking due to low gas. Admittedly I did not measure the gas block hole placement to barrel hole as the barrel was dimpled, could the dimple be off for the anderson low pro? I'm in the mountains hunting so I can't take it apart to check until I get home. Just looking for some experience with the block dimple being wrong for the anderson. Or something I over looked. Brass was good after firing, don't believe it's a mag issue, bcg, buffer or spring issue. I'm kinda leaning toward too little gas.
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