• Caliber: 5.56 NATO
  • Finish: Type III Class 2 Hardcoat Anodized Finish
  • Upper Receiver: Spike's Tactical Forged M4 Flat Top Upper - 7075-T6 Aluminum
  • Handguard: 9-Inch Spike's Tactical CRR M-LOK Rail - 6061-T6 Aluminum
  • M4 Feed Ramps: Yes
  • Muzzle Device: A2 Flash Hider
  • Barrel: 16” 1:7 Twist 5.56 NATO Chrome Lined CMV Barrel
  • Muzzle Thread Pattern: 1/2"-28 TPI
  • Gas Block: Spike's Tactical .750" Low Profile Gas Block
  • Gas Tube: Mid-Length Gas Tube
  • Bolt Carrier Group: Spike's Tactical Mil-Spec M16 Bolt Carrier Group
  • Charging Handle: Mil-Spec Charging Handle
  • High Pressure Tested (HPT) and Magnetic Particle Inspected (MPI)


  • Weight: ~3.97 lbs.
  • Overall Length: ~24.4"


  • AR-15 lower receivers


  • 1x Spike's Tactical 16" Mid-Length 5.56 Complete Upper w/ FSB
  • 1x Spike's Tactical Mil-Spec M16 Bolt Carrier Group
  • 1x Mil-Spec Charging Handle
  • 3x M-LOK Rail Covers
  • 1x QD Swivel


Do you like modern handguards on your AR-15, yet prefer the Mil-Spec A2 style front sight base? The Spike's Tactical complete upper receiver with FSB is an excellent upper for your next AR build.

Starting from the front, this complete upper assembly features a 16-inch CMV steel barrel. Chrome Moly Vanadium barrels are very strong and durable. They offer better protection against corrosion and better heat dissipation. The barrel has a 1:7 twist rifle sling, ideal for a wide range of 5.56 bullet profiles. Moreover, it also has a 1/2"-28 threaded muzzle and comes equipped with an A2 style flash hider.

This upper assembly used a low-profile mid-length gas tube, which offered better performance than the carbine-length gas systems used on most Mil-Spec ARs. The gas system is covered by a 9-inch CRR aluminum M-LOK handguard. The Spike's Tactical CRR M-LOK handguard has covered M-LOK slots on the sides and the bottom, with a full-length Picatinny rail on top, and features a QD sling mount.

Moving on, the Spike's Tactical Forged M4 Flat Top Upper is made from 7075-T6 Aluminum and has a hard coat anodized finish. It features M4 feed ramps for improved reliability, a forward assist, and a port door. It includes the Spike's Tactical Mil-Spec M16 profile Bolt Carrier Group and features a Mil-Spec charging handle.

To maintain the Spike's Tactical quality standards and ensure the quality of the steel, both the barrel and the BCG are High Pressure Tested and Magnetic Particle Inspected.

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