RRA midlength with chrome lined bore and the barrel was turned to gov't profile by Predator Custom Shop. Lower started out as a J&T M4 build about six years ago. Falcon/Ergo side sling mount Tango Down Battlegrip Vickers sling EoTech 512 Matech BUIS extra power extractor w/black insert and o-ring Yankee Hill handguards Magpul trigger guard Viking Tactics light mount, Surefire G2 combo UTG vertical grip I plan on changing to a Spike's vertical grip, adding a Larue EoTech mount, a PRI charging handle, Midwest Industries same plane BUIS, Midwest Industries quick detach sling mounts, RRA 2 stage trigger group, and a Magpul CTR stock. I'm in the process of building 2 other AR's so for now I'm just trying to focus on getting them done enough to shoot.