Whether you're building a custom rifle or replacing an old barrel, your gun will benefit from a new, durable AR15 barrel. Tactical Ambush manufactures our rifle barrels from ER Shaw 4142 hardened chrome moly vanadium steel blanks. They are button rifled with a 1/7 twist rate. This barrel is meant for 55 grain and heavier rounds, and will excel with 72+ grain rounds. When you're looking for a quality barrel that will provide you with accuracy and durability for your AR15, think Tactical Ambush.