M16-profile, full-auto capable bolt carrier group from Sons of Liberty Gun Works. HPT, MPI, shot-peened components, corrosion-resistant finish — engineered for long service life and required for reliable Super Safety operation. 

The Sons of Liberty Gun Works complete bolt carrier group is the dependable heart of a serious AR-15. Every component is precision machined from premium steels, inspected, and assembled to deliver rock-solid reliability under hard use.

This BCG features high-pressure testing (HPT), magnetic particle inspection (MPI), shot-peened components, and a corrosion-resistant manganese-phosphate finish. The carrier is an M16-profile / full-auto capable 8620 alloy, and the bolt is Carpenter Technology 158 alloy — both selected and processed for durability and reliable engagement. Small, thoughtful details like a precision ground gas-key interface, staked hardware, shot-peened critical parts, and a hard chrome-plated firing pin reduce wear and improve longevity.

If you’re building or upgrading a rifle that will run a Super Safety or similar active-reset system, an M16-profile / full-auto capable BCG is required for correct trip engagement and reset. Standard M4-profile or semi-only carriers typically do not provide the carrier geometry necessary for the Super Safety to function reliably.

Built for duty use and long life, the SoLGW BCG is a drop-in, mil-spec assembly that keeps your rifle running when it matters.

Key features

• M16-profile / full-auto capable 8620 alloy carrier — required for Super Safety operation

• Carpenter Technology 158 alloy bolt, shot-peened for strength

• Manganese-phosphate finish for corrosion resistance

• High-pressure tested (HPT) and magnetic particle inspected (MPI)

• Hard chrome-plated firing pin to resist breakage

• 4340 tool-steel extractor & S7 ejector (shot-peened)

• 4130 chromoly gas key with staked hex screws and precision ground gas-key interface

• 4340 chromoly cam pin with solid film lubricant for reduced wear

• Purpose-built for reliability and long service life

Specifications

• Carrier profile: M16 / Full-Auto capable (8620 alloy)

• Bolt: Carpenter Technology 158 alloy, shot-peened

• Extractor: 4340 tool steel, shot-peened

• Ejector: S7 tool steel, shot-peened

• Cam pin: 4340 chromoly with solid film lubricant

• Firing pin: 8640 steel alloy, hard chrome plated

• Gas key: 4130 chromoly, staked with hex screws; precision ground interface

• Finish: Manganese phosphate (corrosion resistant)

• Testing: HPT / MPI; assembled and inspected to SoLGW tolerances