Faxon Firearms ARAK-21 12.50" Upper 5.56x45mm, Black

The ARAK-21 is a gas piston-actuated upper receiver assembly engineered to seamlessly integrate with the standard AR-15 platform. Designed for effortless installation, it requires only the takedown and pivot pins, allowing users to attach it to their lower receiver in under a minute without the need for tools. This innovative upper receiver brings a host of advanced features while maintaining full compatibility with existing AR-15 lower receivers. Each ARAK-21 upper receiver is shipped with one or two Barrel Assembly Units (BAU), depending on the selected package. The BAU includes the barrel, gas block, muzzle brake, gas piston, gas adjuster, and barrel trunnion. The gas adjuster knob, the only removable component of the assembly, offers four settings, three for optimized gas flow and one that completely blocks gas flow for single-shot operation. Built for versatility and reliability, the ARAK-21 upper receiver features a charging block, standard charging handle, lower forearm with screws, three full-length aluminum Picatinny rails, three insulating shims, a bolt carrier assembly, a lower recoil lug with a spring guide rod, and a dual recoil spring system. The package also includes an owner's manual and two Allen wrenches for securing the lower forearm and front Picatinny rails. Due to the ARAK-21 's cutting-edge design, most components are unique and not interchangeable with standard AR-15 upper receiver parts. However, the firing pin, extractor spring, and ejector spring remain compatible, ensuring easy maintenance. With its precision engineering and modular functionality, the ARAK-21 delivers an enhanced shooting experience that redefines the capabilities of the AR-15 platform.

• The upper receiver is machined from aircraft-grade 6061-T6 aluminum billet in a 1-piece design and includes a full-length picatinny rail (MIL-STD-1913) on top, with (3) additional rails on the muzzle end
• Making it a full M4 style quad rail upper, the top picatinny rail is laser-engraved for precise optic placement, providing a robust and versatile platform
• The 12-1/2 inches BAU barrel in 5-1/26 x 45mm has a heavy profile for added durability
• Baus can be interchanged in less than 3 min by removing (6) captive Allen screws on bottom rail using enclosed Allen wrench
• The long stroke variable setting gas piston system offers (3) gas flow options and one for no gas flow, allowing for single-shot operation, with a clean-out port for the gas block
• The ambidextrous charging handle is non-reciprocating, foldable, spring-returned and can be easily relocated from left to right side without tools
• Model 39 inches 8-lug bolt design with an involute profile, compatible with both right and left hand versions, the extractor is positioned at 3 o'clock for smooth operation
• The left hand version can use the same bolt by removing the cam pin, rotating it 180 degree and reinstalling the cam pin for seamless operation
• Self-contained firing pin retention system enclosed in a rectangular bolt carrier that no longer requires a cotter pin, offering a simpler and more reliable design
• The bolted-in hardened steel rail system provides a metal-on-metal wear surface for the bolt carrier, resulting in better wear characteristics and smoother operation
• The ARAK-21 system supports the addition of a folding stock, thanks to a unique recoil system that does not extend beyond the upper receiver, eliminating the noise and feel of a buffer tube cycling back and forth