The Lineage: HK 416 - Sig 516 - Caracal 816
This guide details the disassembly and reassembly of the HK MR556 A1, a civilian variant of the HK416. It covers the proprietary takedown pin mechanism, bolt carrier group components, and the external piston gas system. Key steps include separating receivers, removing the BCG, disassembling the bolt, and accessing the gas system by removing the handguard. The process highlights the unique HK components and their differences from standard AR-15 platforms.











