Undertaker 16-inch Carbine-Gas 1:8 5.56 NATO AR-15 Freefloat M-Lok Handguard Rifle Upper Build Kit

Undertaker 16-inch Carbine-Gas 1:8 5.56 NATO AR-15 Freefloat M-LOK Upper Build Kit

The Undertaker is a 5.56 NATO AR-15 Upper Build Kit built around a 16-inch carbine-length gas platform. The kit centers on a 16-inch Fiddler match grade M4 profile barrel in 416R stainless steel with a 1:8 twist rate and 1/2x28 thread pitch, paired with an A2 birdcage flash hider and a black crush washer. A micro low-profile steel gas block at 0.750 diameter and a carbine-length stainless steel gas tube are included on the front end. The upper receiver is a USA-made slick side billet 6061 aluminum design with an anti-rotation cutout and no forward assist, paired with a 15-inch Unique-ARs Skeleton Hand freefloat M-LOK handguard in a slim profile with a skeleton hand custom cut pattern. BCG and charging handle are not included.

Key Features

• 16-inch Fiddler match grade M4 profile barrel, 416R stainless steel, 1:8 twist, 1/2x28 thread pitch, 5.56 NATO
• Carbine-length gas system
• Carbine-length stainless steel gas tube
• Micro low-profile steel gas block, 0.750
• A2 birdcage flash hider, 1/2x28, black crush washer included
• USA-made slick side billet 6061 aluminum upper receiver, anti-rotation cutout, no forward assist
• Unique-ARs Skeleton Hand 15-inch freefloat M-LOK handguard, slim profile, skeleton hand custom cut pattern
• BCG and charging handle not included

Perfect For

• Builders sourcing a complete 5.56 NATO AR-15 upper build kit with a Fiddler 416R stainless match grade barrel, USA-made slick side billet upper, and Unique-ARs Skeleton Hand slim M-LOK handguard, pairing it with their own bolt carrier group and charging handle
• Shooters building a 16-inch carbine-gas 5.56 NATO platform who prefer to select their own BCG while having the match grade stainless barrel, slick side billet upper with anti-rotation cutout, and slim profile skeleton hand M-LOK handguard covered in one kit
• AR-15 builders who want a Unique-ARs Skeleton Hand freefloat M-LOK handguard with a custom cut pattern on a USA-made slick side billet upper with a Fiddler match grade 416R stainless barrel without sourcing components separately

Barrel and Muzzle Device

The 16-inch Fiddler match grade M4 profile barrel is chambered in 5.56 NATO and constructed from 416R stainless steel with a 1:8 twist rate and 1/2x28 thread pitch. The A2 birdcage flash hider covers the muzzle thread. A black crush washer, a micro low-profile steel gas block at 0.750 diameter, and a carbine-length stainless steel gas tube cover the front end gas configuration on this carbine-length platform.

Slick Side Billet Upper Receiver and Handguard

The USA-made slick side billet 6061 aluminum upper receiver features an anti-rotation cutout and removes the forward assist housing from the upper receiver body for a clean exterior profile. The Unique-ARs Skeleton Hand 15-inch freefloat M-LOK handguard features a slim profile with a skeleton hand custom cut pattern along the handguard body and M-LOK attachment points for accessory mounting. These two components define the exterior structure of the upper assembly on this AR-15 platform.

Follow safe handling and manufacturer instructions. Ensure compliance with all applicable federal, state, and local laws. BCG and charging handle are not included.