Davidson Defense Invictus 18-inch Mid-Gas 1:24 .450 Bushmaster AR-15 Freefloat M-Lok Handguard Rifle Upper Build Kit

Invictus 18-inch Mid-Gas 1:24 .450 Bushmaster AR-15 Freefloat M-LOK Upper Build Kit

The Invictus is a .450 Bushmaster AR-15 Upper Build Kit built around an 18-inch mid-length gas platform. The kit centers on an 18-inch Sepal HBAR profile barrel in 4150 CMV steel with a phosphate finish, 1:24 twist rate, and 5/8x32 thread pitch, paired with a KAK .458 compensator and a black crush washer. A micro low-profile steel gas block at 0.750 diameter and a mid-length stainless steel gas tube are included on the front end. The upper receiver is a Panhead billet aluminum design configured for .458 and .450 Bushmaster with an enlarged .458 ejection port door installed and an ejection port door, rod, and spring included, paired with a 15-inch freefloat M-LOK handguard in black with a partial Picatinny rail section. BCG and charging handle are not included.

Key Features

• 18-inch Sepal HBAR profile barrel, 4150 CMV steel, phosphate finish, 1:24 twist, 5/8x32 thread pitch, .450 Bushmaster
• Mid-length gas system
• Mid-length stainless steel gas tube
• Micro low-profile steel gas block, 0.750
• KAK .458 compensator, 5/8x32, black crush washer included
• Panhead billet aluminum upper receiver, .458 and .450 Bushmaster compatible, enlarged .458 ejection port door installed, ejection port door, rod, and spring included
• 15-inch freefloat M-LOK handguard, black, partial Picatinny rail section
• BCG and charging handle not included

Perfect For

• Builders sourcing a complete .450 Bushmaster AR-15 upper build kit with a Panhead billet upper receiver featuring an enlarged .458 ejection port, Sepal HBAR barrel, and KAK .458 compensator, pairing it with their own bolt carrier group and charging handle
• Shooters building an 18-inch .450 Bushmaster mid-gas platform who prefer to select their own BCG while having the HBAR barrel, mid-length gas system, and 15-inch freefloat M-LOK handguard with a partial Picatinny rail section covered in one kit
• AR-15 builders who want a .450 Bushmaster upper build kit with a Panhead billet upper receiver and KAK .458 compensator at a 5/8x32 thread pitch without sourcing components separately

Barrel and Muzzle Device

The 18-inch Sepal HBAR profile barrel is chambered in .450 Bushmaster and constructed from 4150 CMV steel with a phosphate finish. The twist rate is 1:24 and the thread pitch is 5/8x32, which matches the included KAK .458 compensator. A black crush washer, a micro low-profile steel gas block at 0.750 diameter, and a mid-length stainless steel gas tube cover the front end gas configuration on this mid-length platform.

Panhead Billet Upper Receiver and Handguard

The Panhead billet aluminum upper receiver is configured for .458 and .450 Bushmaster with an enlarged .458 ejection port door installed. An ejection port door, rod, and spring are included. The 15-inch freefloat M-LOK handguard is black with a partial Picatinny rail section and M-LOK attachment points along the body for accessory mounting. These two components define the exterior structure of the upper assembly on this .450 Bushmaster platform.

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