ENHANCED BOLT FULL AUTO 5.56MM BOLT CARRIER GROUP Full-auto bolt carrier with enhanced bolt assembly. 5.56A-45 (.223) If LMT's standard bolt is the infantryman of the gun industry, then their enhanced bolt is the delta operator. This bolt was designed to function effectively in full-auto, suppressed, and short barrel weapon systems, and it is made of materials far more durable than your standard fare. Quite simply, it's the best possible upgrade for your rifle to increase reliability and functionality. The LMTA(R) Enhanced Bolt provides the following: Built from a proprietary material that is not only stronger than the standard bolt but easier to clean as well Mod Mfg: Lmt Defense