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

Kikimora 18-Inch Mid-Gas 1-24 .450 Bushmaster AR-15 Freefloat M-LOK Handguard Rifle Upper Build Kit

This is an AR-15 upper build kit chambered in .450 Bushmaster, built around an 18-inch Sepal HBAR profile 4150 CMV steel barrel with a phosphate finish and a 1-24 twist rate specific to the .450 Bushmaster chambering. The Panhead billet upper receiver with an anodized finish and a .458 SOCOM and .450 Bushmaster ejection port door assembly anchors the front end with a profile purpose-built for the larger bore diameter of this chambering. The 15-inch AIR LITE Series freefloat M-LOK handguard with a monolithic top rail covers the forend with a lightweight and clean accessory-ready profile. BCG and charging handle are not included.

Key Features

• .450 Bushmaster chambering, 18-inch Sepal HBAR profile 4150 CMV steel barrel, phosphate finish
• 1-24 twist rate, 5-8x32 thread pitch
• Mid-length gas system with mid-length stainless steel gas tube
• Micro low-profile steel gas block, .750 inch
• Panhead billet upper receiver, anodized, .458 SOCOM and .450 Bushmaster ejection port door assembly
• Integrated forward assist
• 15-inch AIR LITE Series freefloat M-LOK handguard, monolithic top rail, lightweight design
• KAK .458 compensator, 5-8x32 thread pitch
• Black 5-8-inch crush washer

Perfect For

• AR-15 builders sourcing a .450 Bushmaster upper assembly without BCG or charging handle
• Shooters adding an 18-inch .450 Bushmaster upper to an existing lower with a compatible BCG and charging handle on hand
• Builders who want a lightweight AIR LITE Series handguard with a monolithic top rail in a purpose-built .450 Bushmaster front end

Upper Receiver and Barrel

The Panhead billet upper receiver with an anodized finish anchors the front end with a .458 SOCOM and .450 Bushmaster ejection port door assembly and an integrated forward assist, both specific to the platform requirements of the .450 Bushmaster chambering. The 18-inch Sepal HBAR profile 4150 CMV steel barrel brings a phosphate finish and a 1-24 twist rate to the .450 Bushmaster chamber, threaded at 5-8x32, a thread pitch specific to this bore diameter. The mid-length stainless steel gas tube and micro low-profile steel gas block at .750 inch run a well-matched mid-length gas system along the barrel for the 18-inch profile, keeping the gas timing appropriate for this barrel and chambering combination.

AIR LITE Series Freefloat M-LOK Handguard

The 15-inch AIR LITE Series freefloat M-LOK handguard surrounds the barrel and gas system along the forend with a monolithic top rail running the full length of the handguard for continuous optics and accessory mounting from the upper receiver to the muzzle end. M-LOK slots run along the handguard body for additional accessory attachment across the forend. The lightweight free-float design of the AIR LITE Series keeps the overall front end balanced and purposeful on an 18-inch .450 Bushmaster platform without adding unnecessary weight or bulk along the forend.

Muzzle Device

The KAK .458 compensator threads onto the 5-8x32 muzzle end of the barrel, a thread pitch and caliber designation specific to the .450 Bushmaster bore diameter. The included black 5-8-inch crush washer seats at the barrel shoulder and completes the muzzle hardware for this kit. The KAK .458 compensator is a purpose-built muzzle device for this chambering and thread pitch combination.

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