An Battle Arms Tungstenless AR-15 Carbine Buffer is a crucial component of the rifle's recoil system, working in conjunction with the buffer spring to manage recoil and cycle the action. It's a cylindrical part that slides within the buffer tube and absorbs the impact of the bolt carrier group when the rifle is fired. The moving weights inside the buffer perform the "deadblow" effect to help keep the bolt carrier group from bouncing after it closes on the chamber. Without the proper dead blow effect, the bolt carrier group can bounce, which affects cycling and lock time. Different buffer weights are available, each affecting how the rifle cycles and manages recoil.