Complete BCG assembly with JPBC-4 .308 Low Mass Carrier and JPEB-308 JP EnhancedBolt™ with cam pin, firing pin, and firing pin retainer.
This notice pertains to any rifle based on the large-format AR-10-type or LR-308 platform typically chambered in .308 Winchester, 7.62x51 NATO, or other cartridges requiring the longer magazine format. Be aware that these receiver platforms are not standardized like the AR-15/M16 platform for which most parts are cross-compatible. Before ordering accessories and parts for your large-format rifle, make sure the parts are compatible with your particular platform. The JPBC-4A complete bolt carrier assembly and its parts are compatible with the DPMS family of AR-10 products. With the Armalite/Rock River family of large-frame receivers, this assembly can only be used as a complete bolt carrier assembly group. Interchanging individual components will result in an unsafe configuration. DO NOT under any circumstances mix and match components between the platforms. Only use the complete JP bolt carrier assembly in the Armalite/Rock River platforms.