2AUMK3REV1 Universal Drilling Jig

This item is fabricated to order.

The 2AUMK3 is the newest iteration of our universal pin drilling jigs. It is for 223/556 barrels and has drilling positions for all four common gas block journal sizes (0.625, 0.750, 0.875 and 0.938). It is adjustable axially to accommodate any gas system and pin location. The drill bushing is also adjustable and held with a set screw.

When drilling a melonite/nitride treated gas block, it is recommended to start the hole with a long 3mm end mill (available from McMaster or MSC).

Jig includes muzzle support block, drill bushing, needed set screws and one #31 cobalt drill.