Bear Creek Arsenal BC-15 5.56 NATO 11.5in Bolt Action Style Upper Receiver M4 Barrel 1-7 Twist 1/2×28 Flash Hider Parkerized

Bear Creek Arsenal BC-15 5.56 NATO 11.5in Bolt Action Style Upper Receiver M4 Barrel 1-7 Twist 1/2×28 Flash Hider Parkerized. 56 Nato upper is compatible with any mil-spec AR-15 lower. Magazine not included. Specifications for Bear Creek Arsenal BC-15 5.56 NATO 11.5in Bolt Action Style Upper Receiver: Manufacturer: Bear Creek Arsenal Caliber: 5.56x45mm NATO Barrel Length: 11.5 in Barrel Profile: M4 Barrel Twist Rate: 1-7 Threads per Inch: 1/2×28 Muzzle Device: Flash Hider Finish: Parkerized Color: Black Gun Model: AR-15 Handguard Length: 10 in Gun Rail: M-LOK Gun Make: AR Platform Weight: 4.25 lb Flutes: No Package Contents: Bear Creek Arsenal BC-15 5.56 NATO 11.5in Bolt Action Style Upper Receiver What firearm models does the manufacturer say Bear Creek Arsenal BC-15 5.56 NATO 11.5in Bolt Action Style Upper Receiver is compatible with? The manufacturer suggests that Bear Creek Arsenal BC-15 5.56 NATO 11.5in Bolt Action Style Upper Receiver is compatible with AR-15Bear Creek Arsenal UABA-363-556CM411.517-10ASR: BC-15 5.56 NATO 11.5in Bolt Action Style Upper Receiver M4 Barrel 1-7 Twist 1/2×28 Flash Hider Parkerized