Ultra-Smooth Operation & Enhanced Reliability; Nickel-Boron Finish Available

Matched bolt/carrier set is machined to mil-spec dimensions using the latest manufacturing and quality-control techniques to deliver superb reliability in both semi-auto and select-fire rifles. Carrier is hard-chromed inside and has an M16-type full-length shroud on the underside to trip the auto sear on full-auto/burst rifles. Bolt is magnetic particle inspected to ensure there are no internal flaws to compromise structural integrity and cause premature failure. Fully staked carrier key and tool steel extractor further aid reliable cycling. Laser-engraved Spike’s Tactical logo on the side of the carrier is visible when the ejection port door is open. .223/5.56 fits standard AR-15/M16/M4 rifles and is available with standard MIL-STD-171 5.3.1.2 phosphate finish or with a FailZero EXO™ nickel-boron coating that’s smoother and slicker than hard-chrome for reduced friction and superb wear-resistance in high-intensity applications. 6.8mm SPC enables conversion to the hard-hitting performance of the 6.8mm SPC round. A 6.8 barrel and magazine (both available separately) are necessary to complete the caliber conversion.