AR-15 5.56/.223 18" Stainless Steel Straight Fluted Upper, 1:8 Twist, 12" M-LOK, Triport Muzzle Brake

18" 5.56 Upper: Specs & Features

The AR-15 5.56/.223 18" Stainless Steel Straight Fluted Tactical Upper Assembly is engineered for precision, performance, and durability. Built around a .223 Wylde chamber, this upper offers maximum compatibility and accuracy with both 5.56 NATO and .223 Remington ammunition.

The 18" 416R stainless steel HBAR barrel is straight fluted to reduce weight and improve heat dissipation. With a 1:8 right-hand twist and button rifling, this barrel excels in stabilizing a wide range of bullet weights, making it ideal for both long-range accuracy and tactical use.

The upper is finished with a black nitride triport muzzle brake and 1/2x28 threading, improving recoil management and muzzle control. The included 12" mid-length M-LOK rail allows for the easy attachment of accessories without adding unnecessary bulk.

Key Features:

• Caliber: .223 Wylde (compatible with both 5.56 NATO and .223 Rem)

• Barrel: 18" 416R Stainless Steel, HBAR Contour, Straight Fluted

• Twist Rate: 1:8 RH, Button Rifled

• Muzzle Threads: 1/2x28 with Triport Brake and Crush Washer

• Feed Ramps: M4

• Gas System: Mid-Length Stainless Tube with .750 Low-Profile Steel Gas Block

• Receiver: A3 Flat Top, 7075-T6 Aluminum Forged, Hardcoat Anodized

• Handguard: 12" Free Float Slim M-LOK, Aircraft-Grade Aluminum

• Finish: Black Hardcoat Anodized

• Weight: Approx. 4.7 lbs

• Compatibility: Fits any standard AR-15 lower

• Note: BCG and Charging Handle sold separately

Images may not reflect the exact configuration. Finishes may vary slightly.

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