Alexander Arms Upper Receiver Build Kit AR-15 6.5 Grendel 18″ Stainless Steel Fluted Barrel 5/8″-24 Thread Black

Mil-Spec flat top upper receiver (port door and forward assist installed)
18″ 416R stainless steel, fluted barrel
1:7.5 twist
Threaded 5/8-24 RH
Complete bolt carrier and 6.5 Grendel Bolt
Mid-length Gas tube
Mil-Spec charging handle