MBX Extreme PCC recoil accessories—buffer weights, spring tuning kits, and carrier components—let you dial in the recoil impulse of your competition carbine for consistent cycling and reduced perceived recoil. Getting buffer weight and spring rate right for a specific load and BCG mass directly affects split times and dot tracking, especially on blowback-operated platforms where impulse tuning is the primary lever. Fast same-day shipping on most orders at Shooters Connection.