Davidson Defense Ronin Competition 18-inch Rifle-Gas 1:7.5 6mm ARC AR-15 Freefloat M-Lok Handguard Rifle Upper Build Kit

Ronin Competition 18-inch Rifle-Gas 1:7.5 6mm ARC AR-15 Freefloat M-LOK Rifle Upper Build Kit

The Ronin Competition is a 6mm ARC AR-15 Upper Build Kit built around an 18-inch rifle-length gas platform. The kit centers on an 18-inch government profile 41V50 CrMoV steel barrel with a nitride finish, 5R rifling, 1:7.5 twist rate, and 5/8x24 thread pitch, paired with a GI birdcage flash hider compatible with .308 Winchester, 7.62x39, .300 Blackout, and 6mm ARC, and a black crush washer. A micro low-profile steel gas block at 0.750 diameter and a rifle-length stainless steel gas tube are included on the front end. The USA-made slick side billet aluminum upper receiver features an anti-rotation cutout, paired with a 15-inch ACE Series freefloat M-LOK handguard in black. BCG and charging handle are not included.

Key Features

• 18-inch government profile 41V50 CrMoV steel barrel, nitride finish, 5R rifling, 1:7.5 twist, 5/8x24 thread pitch, 6mm ARC
• Rifle-length gas system
• Rifle-length stainless steel gas tube
• Micro low-profile steel gas block, 0.750
• GI birdcage flash hider, 5/8x24, compatible with .308 Winchester, 7.62x39, .300 Blackout, and 6mm ARC, black crush washer included
• USA-made slick side billet aluminum upper receiver, anti-rotation cutout
• 15-inch ACE Series freefloat M-LOK handguard, black
• BCG and charging handle not included

Perfect For

• Builders sourcing a 6mm ARC AR-15 upper build kit with an 18-inch 41V50 CrMoV nitride barrel with 5R rifling, USA-made slick side billet upper receiver with anti-rotation cutout, and a 15-inch ACE Series freefloat M-LOK handguard, pairing it with their own 6mm ARC bolt carrier group and charging handle
• Shooters building an 18-inch rifle-gas 6mm ARC platform who prefer to select their own BCG while having the 5R rifled nitride 41V50 CrMoV barrel, USA-made slick side billet upper with anti-rotation cutout, and ACE Series freefloat M-LOK handguard covered in one kit
• AR-15 builders who want a 6mm ARC upper build kit with a 5R rifled 41V50 CrMoV nitride barrel, GI birdcage flash hider at 5/8x24, and a USA-made slick side billet upper receiver without sourcing components separately

Barrel and Muzzle Device

The 18-inch government profile barrel is chambered in 6mm ARC and constructed from 41V50 CrMoV steel with a nitride finish and 5R rifling. The twist rate is 1:7.5 and the thread pitch is 5/8x24, which matches the included GI birdcage flash hider, compatible with .308 Winchester, 7.62x39, .300 Blackout, and 6mm ARC. A black crush washer, a micro low-profile steel gas block at 0.750 diameter, and a rifle-length stainless steel gas tube cover the front end gas configuration on this rifle-length platform.

Upper Receiver and Handguard

The USA-made slick side billet 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 15-inch ACE Series freefloat M-LOK handguard is black with M-LOK attachment points along the body 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. Verify compatibility with your specific 6mm ARC lower receiver and bolt carrier group before use.