Bolt Carrier Group SOLGW 5.56 158 Carpenter SP/HPT/MPI


The bolt-carrier group is at the heart of the AR-15, and its quality and function can mean the difference between a high-performance fighting rifle and a jam-o-matic. The Sons of Liberty Gunworks Bolt Carrier Group is a dedicated design for any AR-15 that uses high-quality materials and components to ensure the best possible performance in your gun. Each Sons of Liberty Gunworks AR-15 Bolt Carrier Group includes components made from a number of cutting-edge materials. The bolt itself is machined from Carpenter Technology No. 158 steel, which is heat-treated to military specifications, shot-peened, vibratory tumbled, and full-auto test fired in a complete assembly to ensure performance. The carrier itself is machined from AISI 8620 alloy steel and features a full-auto profile. The carrier is heat-treated, carburized, and stress-relieved.


The interface surface with the gas key is precision-ground to ensure a good fit. The gas key on the Sons of Liberty Gunworks AR-15 Bolt Carrier Group is fitted with Permatex-sealed Grade 8 hex screws, which are torqued and staked to military specs. All other carrier components are made from high-grade materials, and the extractor spring features a Sprinco 5 coil chrome-silicon wire complete with a synthetic elastomer extractor buffer.

• SP (Shot Peened): This process enhances the bolt's durability and resistance to cracking by increasing its fatigue strength.
• HPT (High Pressure Tested): The bolt undergoes rigorous high-pressure testing to ensure it can endure extreme conditions without failure.
• MPI (Magnetic Particle Inspection): This non-destructive inspection method detects surface and near-surface defects, ensuring the bolt is flawless.

These treatments guarantee that the bolt carrier group is both reliable and durable.