AR-15 5.56/.223 20" Nitride Spiral Fluted Upper Assembly – M-LOK, Triport

20" 5.56 Upper: Specs & Features

AR-15 5.56/.223 20" Nitride Spiral Upper Assembly / MLOK / Triport Brake - Precision and Performance in Every Shot

Upgrade your AR-15 build with the AR-15 5.56/.223 20" Nitride Spiral Upper Assembly—engineered for high performance, precision, and long-lasting durability. Whether you're a competitive shooter or a firearm enthusiast, this upper assembly offers superior features to elevate your shooting experience, from improved heat dissipation to enhanced muzzle control.

Designed for Accuracy and Durability: The 20" 4150 CMV HBAR contour barrel is a standout feature in this upper assembly. Its spiral fluting reduces weight and enhances barrel rigidity, ensuring better precision with each shot. Nitride-coated for maximum durability, this barrel offers exceptional corrosion resistance while maintaining superior strength. The .223 Wylde chamber ensures compatibility with both 5.56 NATO and .223 Remington cartridges, giving you the versatility you need for various shooting applications.

Perfect for Long-Range Precision:

• Barrel: The 20" 4150 CMV HBAR is hardened to 26-32 RC and stress-relieved for maximum durability. The 1-8 RH twist and button rifling guarantee smooth, consistent performance, while the nitride triport muzzle brake minimizes recoil and muzzle rise, giving you better control for follow-up shots.
• Gas System: The low profile .750 steel gas block and rifle-length gas tube ensure reliable cycling and smooth operation, reducing wear and increasing the longevity of your upper assembly.
• Handguard: The 15" slim free-floating MLOK rail gives you ample space for customizing your build with accessories like optics, lights, or foregrips. Made from aircraft-quality aluminum, it's both lightweight and durable, with black hardcoat anodizing for superior protection.

Premium Receiver and Components:

• The A3 flat-top upper receiver is forged from 7075-T6 aluminum, ensuring maximum strength and rigidity. Finished with black hardcoat anodizing to military specifications, it provides a solid foundation for any build.
• The M4 feedramps ensure smooth feeding and reliable cycling, while the forward assist and dust cover provide enhanced reliability in all conditions.

Key Features:

• Barrel: 20" 4150 CMV nitride-coated spiral fluted barrel, .223 Wylde chamber, 1-8 RH twist, and M4 feedramps.
• Muzzle Device: Nitride triport muzzle brake to reduce recoil and muzzle rise for faster follow-up shots.
• Gas System: Low profile .750 steel gas block with rifle-length stainless steel gas tube.
• Handguard: 15" free-floating MLOK slim-profile handguard for easy accessory attachment.
• Receiver: A3 flat-top upper receiver forged from 7075-T6 aluminum with black hardcoat anodizing.
• Does not include BCG or Charging Handle – available for separate purchase.

Compatibility:

• Caliber: 5.56 NATO / .223 Remington.
• Compliance: Compliant for most states (CA, NY, NJ, etc.)—verify local laws for specifics.

Does not come with BCG and Charging Handle. Maybe purchased separately. Images may not be an exact representation of the product.

FAQ

Will this upper fit my AR-15 lower?

Yes. It fits any standard mil-spec AR-15 lower receiver and uses a standard 5.56 bolt carrier group and STANAG/AR-15 magazines.

What is a .223 Wylde chamber?

A hybrid chamber that safely fires both 5.56 NATO and .223 Remington while giving the tighter accuracy of a .223-style throat.

Is a bolt carrier group included?

No. The bolt carrier group is sold separately; any standard 5.56 AR-15 BCG will work.

What twist rate does it use?

A 1:8 twist, a versatile rate for 55 gr to 77 gr bullets.

Related: 5.56 NATO & .223 Wylde AR-15 uppers