Davidson Defense Ruin 10.5-inch Carbine-Gas 1:8 5.56 NATO AR-15 Freefloat M-Lok Handguard Pistol Upper Build Kit

Ruin 10.5-inch Carbine-Gas 1:8 5.56 NATO AR-15 Freefloat M-LOK Pistol Upper Build Kit, Right-Side Charging

The Ruin is a 5.56 NATO AR-15 Upper Build Kit built around a compact 10.5-inch carbine-length gas platform with a dedicated right-side charging billet upper receiver. The kit centers on a 10.5-inch cryogenically treated Sandel government profile steel barrel with a phosphate finish, 1:8 twist rate, and 1/2x28 thread pitch, paired with a salt bath nitride two-chamber muzzle brake 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 billet 6061 aluminum right-side charging upper receiver carries a Type III hardcoat anodized finish and accepts right-side charging bolt carrier groups only, paired with a 10-inch freefloat M-LOK handguard in black. BCG and charging handle are not included.

Key Features

• 10.5-inch cryogenically treated Sandel government profile steel barrel, phosphate finish, 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
• Salt bath nitride two-chamber muzzle brake, 1/2x28, black crush washer included
• Billet 6061 aluminum right-side charging upper receiver, Type III hardcoat anodized, accepts right-side charging bolt carrier groups only
• 10-inch freefloat M-LOK handguard, black
• BCG and charging handle not included

Perfect For

• Builders sourcing a compact 5.56 NATO AR-15 pistol upper build kit with a dedicated right-side charging billet upper, cryogenically treated Sandel government profile barrel, and salt bath nitride two-chamber muzzle brake, pairing it with their own right-side charging bolt carrier group
• Shooters building a 10.5-inch carbine-gas pistol platform who prefer to select their own right-side charging BCG while having the cryogenically treated barrel, right-side charging billet upper, and freefloat M-LOK handguard covered in one kit
• AR-15 pistol builders who want a right-side charging billet upper with a Type III hardcoat anodized finish and a 10-inch freefloat M-LOK handguard with a salt bath nitride two-chamber muzzle brake without sourcing components separately

Barrel and Muzzle Device

The 10.5-inch Sandel government profile barrel is chambered in 5.56 NATO and constructed from steel with a phosphate finish and cryogenic treatment. Cryogenic treatment subjects the barrel steel to deep cold temperatures to relieve residual stress in the metal structure. The twist rate is 1:8 and the thread pitch is 1/2x28, which matches the included salt bath nitride two-chamber muzzle brake. 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.

Right-Side Charging Billet Upper Receiver and Handguard

The billet 6061 aluminum upper receiver carries a Type III hardcoat anodized finish and is designed around a dedicated right-side charging system that accepts right-side charging bolt carrier groups only. The 10-inch 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 pistol platform.

Follow safe handling and manufacturer instructions. Ensure compliance with all applicable federal, state, and local laws. BCG and charging handle are not included. This upper receiver accepts right-side charging bolt carrier groups only. Verify BCG compatibility before purchase.