FailZero EXO Nickel Boron 6.5 Grendel Type II BCG, SKU FZ-6.5GRENDEL-BCG, 11.2 oz. Type II is the current SAAMI-standard 6.5 Grendel bolt spec, with different extractor geometry and a larger bolt face than 5.56 BCGs — not compatible with Type I barrels due to headspace differences. EXO nickel boron coating on carrier, bolt, extractor, cam pin, gas key, and firing pin. Upgraded extractor with heavy spring, silicone insert, and o-ring. Fully assembled.