Davidson Defense Three-Five-O 16-inch Carbine-Gas 1:16 .350 Legend AR-15 M-Lok Rifle Full Build Kit

Three-Five-O 16-Inch Carbine-Gas 1-16 .350 Legend AR-15 M-LOK Rifle Full Build Kit

This is an AR-15 full build kit chambered in .350 Legend, centered on a 16-inch M4 profile steel Balmung .350 Legend barrel with a phosphate finish, a 1-16 twist rate, and a carbine-length gas system. The Panhead billet upper receiver with a .458 ejection port door anchors the front end, a purpose-built receiver feature for the larger case diameter of the .350 Legend chambering. The 15-inch freefloat M-LOK handguard with a full-length Picatinny top rail and integrated QD sling mounts covers the forend. A complete AR-15 bolt carrier group made in the USA and a Mil-Spec M4 charging handle complete the upper side. A .308 GI Birdcage flash hider in 5-8x24 thread pitch closes out the muzzle end. The lower completion package covers a complete Mil-Spec AR-15 lower parts kit, a Mil-Spec heavy-duty 6-position buffer tube, a standard AR-15 carbine buffer at 3 oz., a standard AR-15 carbine recoil spring made in the USA, a Mil-Spec AR-15 M16 receiver end plate, and a Mil-Spec AR-15 carbine castle nut. A SOPMOD style collapsible stock in black with storage compartments and integrated QD sling mounts closes out the rear end. Lower receiver not included.

Key Features

• .350 Legend chambering, 16-inch M4 profile steel Balmung barrel, phosphate finish
• 1-16 twist rate, 5-8x24 thread pitch
• Carbine-length gas system with carbine-length stainless steel gas tube
• Micro low-profile steel gas block, .750 O.D.
• Panhead billet upper receiver, .458 ejection port door
• AR-15 .223 and 5.56 ejection port door with rod and spring
• 15-inch freefloat M-LOK handguard, full-length Picatinny top rail, integrated QD sling mounts, no anti-rotation tabs
• Complete AR-15 bolt carrier group, made in the USA, 5.56, .223, .300, .350 compatible
• Mil-Spec AR-15 M4 charging handle
• .308 GI Birdcage flash hider, 5-8x24 thread pitch
• Black 5-8-inch crush washer
• Complete Mil-Spec AR-15 lower parts kit
• Mil-Spec heavy-duty AR-15 6-position buffer tube
• Standard AR-15 carbine buffer, 3 oz.
• Standard AR-15 carbine recoil spring, made in the USA
• Mil-Spec AR-15 M16 receiver end plate
• Mil-Spec AR-15 carbine castle nut
• SOPMOD style collapsible stock, black, storage compartments, integrated QD sling mounts

Perfect For

• AR-15 builders who need everything above the lower receiver for a .350 Legend build
• Shooters pairing this kit with an existing stripped or complete AR-15 lower receiver
• Builders who want a complete .350 Legend rifle component set with a Panhead billet upper, freefloat M-LOK handguard, and SOPMOD stock covered in one kit

Upper Assembly

The Panhead billet upper receiver anchors the front end with a .458 ejection port door, a purpose-built feature for the larger case diameter of the .350 Legend chambering that a standard AR-15 ejection port does not accommodate as cleanly. The 16-inch M4 profile steel Balmung barrel brings a phosphate finish and a 1-16 twist rate to the .350 Legend chamber, threaded at 5-8x24, a thread pitch specific to this bore diameter. The carbine-length stainless steel gas tube and micro low-profile steel gas block at .750 O.D. run a carbine-length gas system along the barrel for the 16-inch profile. The 15-inch freefloat M-LOK handguard surrounds the barrel and gas system along the forend with a full-length Picatinny top rail running the entire length of the handguard for optics and accessory mounting, integrated QD sling mounts built into the handguard body, and M-LOK slots along the remaining handguard surfaces for additional accessory attachment. The handguard does not include anti-rotation tabs, a design characteristic of this specific unit.

Bolt Carrier Group and Charging Handle

The complete AR-15 bolt carrier group is made in the USA and compatible with 5.56, .223, .300, and .350, making it a well-suited choice for this .350 Legend chambering. The Mil-Spec M4 charging handle pairs with the BCG inside the upper receiver to complete the upper interior and finish the front end of the build.

Muzzle Device

The .308 GI Birdcage flash hider threads onto the 5-8x24 muzzle end of the Balmung barrel, a thread pitch and caliber specification suited to the .350 Legend bore diameter. The included black 5-8-inch crush washer seats at the barrel shoulder and completes the muzzle hardware for this kit.

Lower Completion Components

The complete Mil-Spec AR-15 lower parts kit covers the full internal lower component group, including the fire control group, magazine catch, bolt catch, and all associated pins and springs. The Mil-Spec heavy-duty 6-position buffer tube, standard AR-15 carbine buffer at 3 oz., and standard AR-15 carbine recoil spring made in the USA form the buffer system at the rear of the lower. The Mil-Spec AR-15 M16 receiver end plate and Mil-Spec AR-15 carbine castle nut lock the buffer tube down cleanly at the rear of the lower receiver. The SOPMOD style collapsible stock in black closes out the rear end with storage compartments and integrated QD sling mounts built into the stock body.

Follow safe handling and manufacturer instructions. Ensure compliance with all applicable federal, state, and local laws. Lower receiver not included.