This Alexander Arms AR-15 Entry Upper Receiver comes fully assembled and ready to install on any standard small pin lower receiver. Chambered for the awesome 50 Beowulf cartridge, this upper squeezes 50 Caliber firepower into a standard AR-sized envelope, offering shooters an immense step up the power scale compared to a traditional 223 Remington. An excellent choice for close- to medium-range hunting or home defense, the Entry Upper's short 16.5" Barrel keeps it compact and maneuverable in tight spaces, as well as reasonably lightweight. Features include a Forged 7075-T6 Aluminum Flat-Top Receiver for adding optics and/or iron sights, 2-Piece Mid-length Polymer Handguards, a Picatinny Rail Gas Block, complete bolt carrier group, charging handle and one 7-Round Magazine.
- This upper comes equipped with a Forward Assist and Brass Deflector Only. For increased reliability, the ejection port has been enlarged in order to give the larger 50 Beowulf cartridge cases room to eject. As modified, this upper does not accommodate or include an ejection port door.
- Barrel diameter under the handguard is 0.980", tapering to 0.907" under the gas block, and finally tapers down to 0.775" at the muzzle. The Single Rail Gas Block is proprietary to the barrel's unique 0.907" Outside Diameter.
- Due to the 50 Beowulf's recoil, use of a Fixed Stock or Durable Collapsible Stock such as a MagPul UBR or ACE Hammer is recommended.
- Upper Receiver: Modified A3 Flat-Top (No Ejection Port Door)
- Barrel Length: 16.5"
- Barrel Contour: Heavy, Tapered
- Barrel Material: Chrome Moly Vanadium Steel
- Muzzle Thread Pattern: None
- Chrome Lined: No
- Barrel Finish: Parkerized
- Twist Rate: 1 in 20"
- Chamber: 50 Beowulf (12.7x42mm)
- M4 Feed Ramps: No
- Muzzle Device: None
- Gas System Length: Mid
- Gas Block Diameter: 0.907"
- Handguard: 2-Piece Polymer w/Heat Shield, A2-Style
- Sights: None
- Bolt Carrier Assembly Included: Yes
- Bolt Carrier Type: 50 Beowulf Compatible Carrier
- Includes Single Rail Gas Block, 7-Rnd Magazine
- Weight: 4.45 lbs
- Upper does NOT have an ejection port door