The Gorilla Machining Complete Bolt Head Assembly is machined from durable Carpenter 9310 steel, and shot peened for proper stress relief. A MIL-SPEC heavy phosphate finish has been applied for long term durability. As an added step to ensure they are free from material defect, these bolts are individually magnetic particle inspected. For maximum reliability, the extractor features an o-ring booster.
This bolt head assembly is designed for use with 5.56 NATO / .223 Remington, and .300 Blackout.