Noveske Bolt Features The Noveske Bolt is machined from 158 Carpenter steel a premium alloy chosen for its strength and resistance to the stresses of repeated cycling under high pressure. Every bolt is shot peened to relieve surface stress and extend fatigue life then magnetic particle tested to catch any hidden flaws before it ships. This level of quality control mirrors what Noveske applies to the bolts installed in its own complete rifles. That consistency gives AR-15 owners confidence the part will perform as reliably as a factory original. Built to function across 5.56 NATO .300 AAC Blackout and 22 Nosler chamberings this bolt gives owners of multi-caliber AR builds a single dependable component across barrel swaps. Its compatibility with small bolt carriers makes it a straightforward fit for a wide range of AR-15 upper configurations. Finished in black it matches standard AR bolt carrier group finishes without drawing attention. Shooters replacing a worn bolt or building a dedicated spare for a hard-use rifle will find this a trustworthy choice. Noveske Bolt Specifications Manufacturer: Noveske Model: Bolt Compatible Hosts: AR-15 Caliber: 5.56 NATO / .300 AAC Blackout Material: 158 Carpenter Steel Color: Black Features: Shot Peened Magnetic Particle Tested Available At: GrabAGun