Gemtech

UPPER RECEIVER - Mil-Spec with Indexing Marks and M4 Feed Ramps. 7075-T6 Aluminum, Type III Hard Coat AnodizedBARREL - 4150CMV Steel, Stress Relieved, Armornite® Treated, 1:8 Twist, 5R Rifled, GVAC™ Profile, Nickle Boron Coated barrel Extension, 1/2X28 TPI Muzzle ThreadsGAS SYSTEM - Pinned Low-Pro GVAC™ Gas Block, 4140CM Steel, Mid-Length GVAC™, Direct-ImpingementMUZZLE DEVICE - Gemtech ETM™ Flash Hider, 4140CM SteelBOLT CARRIER GROUP - Carpenter 158 steel bolt, 8620 Steel Carrier, Mil-Spec MP...