Sons of Liberty Gun Works looks at the bolt carrier group as the heart of the gun. If the gas port is the lungs, then the bolt carrier group is the heart. It’s what drives the entire gun. If you look at the AR platform’s cycle of operations, everything happens around the bolt carrier group. Locking, unlocking, extracting, ejecting…all of it begins with the bolt carrier group.
-Manganese phosphate finish for corrosion resistance
-High Pressure Tested (HPT) and Magnetic Particle Inspected (MPI)
-Hard chromed bore and gas key
-Carpenter Technology 158 alloy bolt (shot peened)
-4340 Tool steel extractor (shot peened)
-S7 Tool steel ejector (shot peened)
-Full auto profile 8620 alloy carrier
-4130 Chromoly gas key with staked hex screws
-4340 Chromoly cam pin
-8640 steel alloy firing pin with chrome plating
TEST FIRE DISCLAIMER:
Many of the manufacturers whose products we carry will have a standardized test fire protocol for not only their complete firearms as well as parts such as upper receiver groups and bolt carriers. Because of this test fire protocol, some items will show evidence of the test fire process such as brass and carbon residue on internals or brass markings on case deflectors.
Great company to buy from 
