02-06-2020, 06:55 PM
A method I use to check gas block/barrel port alignment that works quite well. I shove a tight fitting piece of surgical tubing over the gas tube with the gas block and tube installed but not yet completly torqued, but snug. I blow air, from my mouth thru the tube while moving the gas block around. I can feel the pressure change as the alignment is least restrictive. Then I torque the block screws and check that it still feels good and feel around for any serious leaks I might need to keep an eye on until fouling seals up things real good.