AR57 AR-15 Generation 2 A3 Upper Receiver Assembly 5.7x28mm FN 16" Barrel

Product #: 326990 AR57 #: AR57-001.16 L UPC #: 094922395689
Ships 12/04/2015 from MidwayUSA
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  • Information
The AR57 Upper Receiver Assembly converts an AR-15 to shoot 5.7x28 FN ammunition. The unique upper design loads on top and accepts FN PS90 magazine (not included) and ejects downward through the AR-15 magwell. This upper is precision machined from a one piece aluminum forging. The integrated picatinny-style quad rail system allows attachment of various accessories. A parkerized chrome alloy bolt and full-floated barrel ensure reliability and accuracy. The teflon-infused hard coat anodized aluminum upper and rails gaurantee durability for years of shooting enjoyment. The updated charging handle and magazine release of the Generation 2 allows for easy manipulation of the controls. New and improved lightening features, such as the fluted barrel, shave a pound of this receiver when compared to the Generation 1 upper assemblies. The top feed and bottom eject also help to make this upper fully functional for right or left handed users. A carbine style (3 1/2 inch) buffer is included, rifle length stocks require the AR57-A2 buffer (6 inch), which is sold seperately.

Technical Information
  • Upper Receiver: A3 Flat-Top
  • Barrel Length: 16"
  • Barrel Contour: Fluted, heavy
  • Barrel Material: 4140 Chrome Moly Steel
  • Muzzle Thread Pattern: 1/2"-28
  • Chrome Lined: No
  • Barrel Finish: Parkerized
  • Twist Rate: 1 in 8.5"
  • Chamber: 5.7 x 28mm FN
  • M4 Feed Ramps: N/A
  • Muzzle Device: A2 Flash Hider
  • Gas System Length: Carbine
  • Gas Block Diameter: 0.750"
  • Handguard: Free-Float Quad Rail
  • Sights: None
  • Bolt Carrier Assembly Included: Yes
  • Bolt Carrier Type: N/A
  • Extras: Single Rail Gas Block

Please Note: Installation of AR-15 upper assemblies with certain features including, but not limited to: flash hiders, bayonet lugs, and threaded muzzles may violate state and/or local laws.

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