Alexander Arms DIY 6.5 Grendel upper parts kit. Includes 6.5 Grendel 16" Chrome Moly Barrel with 1:7.5 twist, Melonite finish, 6.5 Grendel Bolt Carrier, Mil-Spec Upper Receiver (Port Door and Forward Assist Installed), 5/8 x 24 Thread Muzzle Brake, Buffer Tube Spring, .875 Gas Block, Mid-Length Gas Tube, 10 Round Magazine, and Mil-Spec Charging Handle Aluminum. Note: Upper kit does not include a barrel nut or rail to allow installation of the user’s preferred rail system.