18" 400 Legend Medium Carbine M-LOK Upper Assembly

Hunt-ready performance with less recoil, more punch.

The 18" 400 Legend M-LOK Upper Assembly is built for hunters who need straight-wall compliance without sacrificing power or precision. Featuring a nitride-treated 18" barrel, medium profile, and carbine-length gas system, this upper delivers consistent sub-MOA performance with modern 400 Legend ballistics. It’s built on a mil-spec forged upper, with a steel nitrided gas block, American-made M-LOK handguard (style may vary), and nitrided A2 flash hider. Assembled with Permatex 242 and AEROSHELL 33MS for reliability in the field. BCG and charging handle not included. Backed by a Limited Lifetime Warranty.

Specifications

• Barrel Finish: Nitride / Melonite
• Barrel Profile: Medium
• Cartridge: 400 Legend
• Barrel Length: 18"
• Gas System: Carbine
• Twist Rate: 1:16
• BCG / Charging Handle: Not Included
• Handguard: American-Made M-LOK (style may vary)
• Muzzle Device: Nitrided A2 Flash Hider
• Origin: Made in the USA

Why 400 Legend?

The 400 Legend offers 25% more energy than 350 Legend and similar energy to 450 Bushmaster—while producing 20% less recoil. It’s the optimal solution for straight-wall states, delivering serious hunting power with enhanced control and shot placement.