AO PRECISION PREMIUM MIL-SPEC PHOSPHATE BOLT CARRIER GROUP - 158 HPT/MPI BCG
Military surplus 158 Bolt carrier groups manufactured by AO Precision to the exacting standards of the US Military. AO makes these HPT / MPI BCG's for other Military contractors, 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
- 158 Carpenter Steel
- Shot Peened
- High Pressure Tested (HPT)
- Magnetic Particle Inspected (MPI)
Mil Spec Carrier
- 8620 Aircraft Grade Steel
- Full Mass M-16
- 4140 Steel per ASTM A108, cold drawn and stress relieved BHN 187-22
- Phosphate Finish
- Extractor Spring
- Black Extractor Insert
- Viton O-Ring
- 4130 Profile Extruded Steel
- Grade 8 Hardware
- Properly Staked
- Chrome Interior
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.
These are machined to tight tolerances and will need to be well lubricated during break-in.
