03-14-2022, 05:27 AM
...a couple of ways to check gas block alignment using calipers:
1. Measure the distance from the back edge of the gas block to the rear edge of the port hole inside gas block. Take measurement from stepped edge of barrel gas journal to rear edge of gas port on barrel, compare the two. This will identify if you can abut the gas block up against the stepped edge or have to have a gap. This "gap" is to typically to accommodate older handguards/front sights that had the handguard retaining plate, ala older M16 and current MIL M4's using the triangular front sight. If you need the "gap", some heavy paper stock or business card can be used as a shim spacer when you reattach your gas block. You can also use feeler gauges if you have them.
2. Measure the diameter of the gas port hole in the gas block, measure the diameter of the gas port hole in the barrel, compare the two. Some brands of gas blocks drill a larger, "oversized" gas port in the gas block so it would overlap the barrels gas port and allow some "wiggle room" on the alignment of the two.
Good luck!
1. Measure the distance from the back edge of the gas block to the rear edge of the port hole inside gas block. Take measurement from stepped edge of barrel gas journal to rear edge of gas port on barrel, compare the two. This will identify if you can abut the gas block up against the stepped edge or have to have a gap. This "gap" is to typically to accommodate older handguards/front sights that had the handguard retaining plate, ala older M16 and current MIL M4's using the triangular front sight. If you need the "gap", some heavy paper stock or business card can be used as a shim spacer when you reattach your gas block. You can also use feeler gauges if you have them.
2. Measure the diameter of the gas port hole in the gas block, measure the diameter of the gas port hole in the barrel, compare the two. Some brands of gas blocks drill a larger, "oversized" gas port in the gas block so it would overlap the barrels gas port and allow some "wiggle room" on the alignment of the two.
Good luck!