The RB5015HD is a specially engineered Heavy Damped KynSHOT for the 9MM PCC application.  The hydraulic fluid and seals are made to meet mil- spec requirements and have an ambient temperature operating range of -30F to +150F. The KynSHOT uses patented hydraulic shock absorption technology to dampen the impact of the bolt at the rear of its travel and to dampen the forward impact of the buffer’s weight as it chambers the next round. Its weight and length have been optimized for the 9MM application so that it runs reliably, softens recoil, smooths out the action, and stops just behind the bolt catch.