Made for 7.62X51 / 308 Cal
HPT/MPI Tested and Marked
9310 Hardened Steel Bolt,
17-4 Stainless Steel Firing Pin (Heat treated to H900 Condition)
8620 carrier and gas key.
Hardened extractor S7 tool steel.
The group comes fully assembled with properly torqued and staked gas key
Made in the USA