Bolt Carrier Group – Chrome Phosphate – HPT/MPI

AR/M16 Bolt Carrier Group – Chrome Phosphate – HPT/MPI
Your bolt carrier group (BCG) is the lifeline of your AR-15. Designed for AR-15 and M16 builds, this group features high-end retaining and firing pin, gas key, and expert assembly, machined from 9310 alloy and laser engraved.  The E2 bolt carrier group works better and provides longer lasting performance for your rifle build.

BCG Includes:

Bolt precision machined from 9310 alloy; carburized/case hardened & shot peened
HP proof testing, 100% using a high pressure M197 or SAAMI commercial equivalent, without evidence of failure
MPI testing after above, 100% inspection per ASTM E1444 using a standard 5 turn magnetizing coil with a current of 200 to 300 amperes. Circular and longitudinal continuous magnetization and a wet fluorescent solution shall be used. Conformance to MIL-STD-410 is required within ASTM E1444
Ultrasonically cleaned and manganese phosphated – 2 hours accelerated Salt Spray & 48-hour endurance Salt Spray completed on each lot
Markings laser engraved (HPT=High Pressure Tested, MPI=Magnetic Particle Inspection)
Extractor, machined 4140 Tool steel alloy, hardened with manganese phosphate
Extractor Pin, precision machined and ground AMS6440/52100 Bearing grade steel retaining pin
Extractor Spring, 5 coil, ASTM Grade A 228 wire stock, stress relieved, Tensile Strength of 393,000 PSI Max, 80 Durometer Per AMS-R-6855 black insert
Extractor Spring O-Ring, Viton (FKM) Fluoropolymer Elastomer
Ejector, S7 shock resistant tool steel alloy, hardened, shot peened per ASTM B851/SAE AMS2430, manganese phosphate
Ejector Spring, ASTM Grade A 228 wire stock, heat treated, stress relieved – Tensile Strength of 376,000 PSI Minimum
Gas Rings, Steel Corrosion Resistant Per AMS 5906 – X3
Carrier machined from 8620 alloy, full auto profile, heat treated, ultrasonically cleaned, hard chrome bore, manganese phosphate – 2 hours accelerated Salt Spray & 48-hour endurance Salt Spray completed on each lot
Gas Key machined from 4130 chromoly steel alloy, heat treated, hard chrome internal & manganese phosphate
Socket Cap Head Screw, steel, grade 4037 per ASTM, heat treated & manganese phosphate 2x
Gas Key is installed with Permatex aviation gasket sealer, torqued to 55-foot pounds, pneumatically steaked and break away tests performed to spec
Cam Pin, precision machined 4340 chromoly steel alloy, heat treated, manganese phosphate & Dry Film Lubricant
Firing Pin, precision machined 8740 steel alloy, heat treated, precision ground & hard chrome plate
Firing Pin Retaining Pin, carbon steel ASTM A510, heat treated & manganese phosphate
All material, components and packaging made in the USA