JP Enhanced 9mm AR Bolt – Machined to the same exacting tolerances as our bolt carriers this second generation 9mm bolt assembly is an entirely new design that eliminates the need for a central mass (slug) to readily function with our 9mm JP Silent Captured Spring without compromising bolt weight and reliability. In fact when combined with our JPSCS-9MM you have the heaviest most reliable 9mm operating system that dramatically reduces bolt bounce while improving accuracy. – This bolt assembly is .9 oz. heavier than the Rock River Arms 9mm bolt with its central mass removed. When used in conjunction with the Silent Captured Spring the complete JP 9mm operating system is slightly heavier than the complete RRA bolt and buffer some of the bolt mass having been transferred to the SCS in our system. – Features: – Reduced stroke length for faster firing impulse when used with JPSCS2-9MM – Corrosion-resistant 416SS construction – Designed for optimal function with JPSCS2-9MM for a heavier operating system that reduces bolt bounce while improving reliability and accuracy – Tighter firing pin channel to reduce pin wear – Rock-hard nitride finish provides remarkable natural lubricity and a fine cosmetic finish – Includes firing pin and retainer pin