Out of curiosity, how do you guys go about ensuring that you have proper gas block alignment with the barrel port on barrels that aren't slotted or drilled for pinned gas blocks? Most guys I know just eye ball it and then shoot to confirm that everything is working. I understand that the port on the gas block is larger than that of the barrel so there is some wiggle room. Still, that method has always bugged me as I think a partially obstructed gas port could result in pressure-related reliability issues. My method: I seal the muzzle-end of the barrel by wrapping 100 mph tape around the barrel extension. Then I will use a compressor to run about 40 PSI of air through the gas tube as I slide the gas block back and forth. I listen to the air flowing out of the muzzle and then tighten the gas block screws when it sounds like I'm getting the largest volume of air from the muzzle. I will then remove the gas block and lightly dimple the areas where the set screws have scored the underside of the barrel. Is there a better way of doing this? Wanna kill these ads? We can help!