Staking carrier key screws prevents them from backing out under extended use. If you don’t use the right tools for this it can damage the gas key, screws or carrier. The Brownells carrier key staking tool enables you to stake the keys with precision from the sides. The carrier key staking tool holds the carrier in place precisely. You stake the keys by tightening four hex screws which dimple the sides of the gas key. An additional screw holds the carrier tightly in the precision machined tool. To prevent this screw from marking the carrier, its tip has been machined flat. For long-life, the tip of each screw is hardened to Rc 58-62. The carrier key staking tool is precision machined from 1018 carbon steel and given a black oxide finish. The tool is 3” (7.62cm) long, 2” (5.1cm) wide and 2” high.
You may find this video on how to build an M16 of interest.
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