09-03-2015, 10:05 PM
I put an adjustable gas block on my 20" Shilen barrel with a PSA six position collapsable stock and use a carbine buffer and the supplied spring. I had to back my GB adjustment screw pretty far out for the rifle to lock on an empty mag. I had a T-2 and an H-2 buffer but didn't need them. From everything I read most 20" barrels are rarely over gassed but I put a JP adjustable gas block on my rifle just to be on the safe side.
Fortunately my upper reciever was square and I had a good fit between my barrel and upper reciever. I put blue Loctite on the barrel extension and gas block. When I zeroed my Vortex scope I needed very little windage adjustment when sighting in my rifle. You might consider a 20 MOA scope mount if you intend on shooting long range. With my 20 MOA mount I have enough adjustment to go past 1000 yards. My 16" 6.5 Grendel has enough elevation adjustment to make 700-800 yards depending on my load using a RRA one piece cantilever mount with no cant.
Fortunately my upper reciever was square and I had a good fit between my barrel and upper reciever. I put blue Loctite on the barrel extension and gas block. When I zeroed my Vortex scope I needed very little windage adjustment when sighting in my rifle. You might consider a 20 MOA scope mount if you intend on shooting long range. With my 20 MOA mount I have enough adjustment to go past 1000 yards. My 16" 6.5 Grendel has enough elevation adjustment to make 700-800 yards depending on my load using a RRA one piece cantilever mount with no cant.