Fte, ftf bca 20" grendel.

[VASCAR2]

Sounds like to little gas to me. I wouldn’t trust the dimples on the bottom of the barrel to align properly with a random gas block. I always measure the distance of the gas port to the shoulder of the barrel. I then verify the gas hole location from the edge of the gas block. I make sure my measurements are correct and set my gas block over the gas port. I use a lead pencil to mark my barrel but always re measure before tightening down the gas block. Fortunately this has always worked for me and I never had to remove a gas block for misalignment.


If you remove the gas block I suggest you measure the gas port. I’ve read you can get close using drill bits but I can get a fairly close measurement with calipers. The info I have is a 20” 6.5 Grendel should have a .0935” gas port.