AS Designs MP5 Hammer - S7 Tool Steel - Black Oxide Finish

AS Designs MP5 Hammer - S7 Tool Steel - Black Oxide Finish

Optimize the reliability and cyclic smoothness of your hybrid roller-delayed setup with the AS Designs Custom MP5 Hammer. Engineered specifically for HK-pattern platforms running aftermarket AR-style lower receivers—such as ARMP5 and Leber lowers utilizing mil-spec Fire Control Groups (FCGs)—this hammer eliminates the persistent cyclic friction and geometry issues common to converted platforms. Unlike standard AR-15 hammers that have been crudely ground down or rounded after the fact, the AS Designs hammer is an entirely bespoke, ground-up design precision-machined with correct engagement radii to ensure flawless timing and interface with the roller-delayed bolt carrier.

By establishing ideal clearance and hammer face geometry, this component significantly reduces drag against the bolt carrier as the action cycles rearward. This reduction in resistance optimizes cyclic bolt speed and allows shooters to eliminate the awkward recoil spring buffer typically required in full-size adapted lower receivers. Precision-machined from extreme-shock S7 tool steel, heat-treated for maximum impact endurance, and protected with a corrosion-resistant black oxide finish, the AS Designs MP5 Hammer is compatible across all MP5 and MP5K variants, as well as rifle-caliber HK platforms including the G3, HK91, HK33, HK53, and HK93.

Features

Purpose-Built Roller-Delayed Geometry:
Engineered from a clean slate rather than re-profiling standard AR-15 components, delivering correct arc geometry, sear engagement, and carrier clearance specifically tailored for roller-delayed bolt groups.

Substantially Reduced Bolt Carrier Drag:
Eliminates excessive upward friction and binding against the bottom of the carrier during cycling, promoting smooth, reliable bolt travel and consistent round stripping from magazines.

Eliminates Aftermarket Lower Buffer Requirements:
Optimized profile allows shooters to completely remove the auxiliary recoil spring buffer often mandated in full-size AR-FCG converted lower receivers, streamlining maintenance and internal components.

Severe-Shock S7 Tool Steel Construction:
Machined from ultra-durable S7 tool steel—renowned for extreme shock and high-impact resistance—ensuring the hammer resists deformation under repeated, hard-hitting carrier impacts.

Universal HK Platform Compatibility:
Engineered to drop into AR-adapted lowers across all MP5 and MP5K makes and clones, as well as larger-caliber roller-delayed systems including G3, HK91, HK93, HK33, HK53, and HK32 rifles.

Protective Black Oxide Finish:
Treated with a durable, non-reflective black oxide coating that safeguards the tool steel from corrosion, fouling, and wear without adding dimensional buildup to precision surfaces.

Specifications