AO PRECISION PREMIUM NITRIDE BOLT CARRIER GROUP - HPT/MPI
These premium 9310 Bolt carrier groups are manufactured by AO Precision to the highest standards of top tier manufacturers within the industry. AO makes these HPT / MPI BCG's for other Military contractor juggernauts, such as FN America. All bolts are rigorously inspected and are individually High Pressure Tested and then go through a Magnetic Particle Inspection.Mil Spec Bolt
- 4140 Steel per ASTM A108, cold drawn and stress relieved BHN 187-22
- Black Nitride Finish
- Extractor Spring
- Black Extractor Insert
- Viton O-Ring
Please note: These BCG's are considered premium because of the materials used and the Military Spec requirements that are adhered to during the manufacturing process. The HPT/metallurgy equipment and processes that these go through are very hard to find and very expensive. These are battle proven (literally), but they may not be as pretty as other BCG's out there.