Moriarti AR-15 300 Blackout 16" Stainless Straight Fluted Upper Assembly with M-LOK

AR-15 Line

AR-15 300 Blackout 16" Stainless Straight Fluted M-LOK Upper | Moriarti Arms

Step into the world of subsonic and supersonic performance with the Moriarti Arms AR-15 300 Blackout 16" Stainless Steel Upper Assembly. Designed for tactical reliability and versatility, this upper brings sleek stainless steel looks and functionality to your AR-15 platform — no proprietary parts required.

Upper Assembly Features:

• Barrel: 16” HBAR contour barrel made from 416R stainless steel, straight fluted for improved cooling and weight reduction. Hardened to 26-32 RC and stress relieved.

  • Chambered in 300 AAC Blackout

  • 1:8 twist rate

  • Threaded 5/8x24, topped with nitride triport muzzle brake and crush washer

  • M4 feedramps for reliable cycling

• Gas System:

  • Carbine-length stainless steel gas tube

  • Low pro .750 steel gas block, nitride coated for durability

• Upper Receiver:

  • Moriarti A3 flat top, forged from 7075-T6 aluminum

  • Black hardcoat anodized per MIL-A-8625 Type III

  • Forward assist, dust cover, included

  • M4 feed ramps for smoother feeding

• Handguard:

  • Moriarti 12” Free-floating M-LOK handguard

  • Slim, aircraft-grade aluminum construction

  • Black hardcoat anodized finish

  • Design may vary slightly depending on availability, same spec quality ensured

Caliber Compatibility

No special parts needed — use your standard .223/5.56 BCG and magazines to run 300 Blackout. Simply install this upper on your existing mil-spec AR-15 lower.

Please Note:

• BCG and Charging Handle not included

• Images may vary slightly depending on handguard availability, the same excellent quality

• Compatible with virtually any mil-spec AR-15 lower receiver

Want to complete your build? Check out the Moriarti AR-15 Lower Receivers.