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

Three-Five-O 16-Inch Carbine-Gas 1-16 .350 Legend AR-15 M-LOK Rifle Complete Upper

This is a complete AR-15 upper chambered in .350 Legend, built around a 16-inch M4 profile steel Balmung .350 Legend barrel with a phosphate finish and a 1-16 twist rate. 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. A carbine-length stainless steel gas tube and micro low-profile steel gas block at .750 O.D. run the carbine-length gas system, and the 15-inch freefloat M-LOK handguard with a full-length Picatinny top rail and integrated QD sling mounts covers the forend. A .308 GI Birdcage flash hider at 5-8x24 closes out the muzzle end. A complete AR-15 bolt carrier group made in the USA and a Mil-Spec M4 charging handle complete the upper component set.

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

Perfect For

• AR-15 builders pairing a complete .350 Legend upper with an existing lower
• Shooters adding a 16-inch carbine-gas .350 Legend upper to an AR-15 lower they already own
• Builders who want a BCG and charging handle included with a Panhead billet upper and freefloat M-LOK handguard in one complete .350 Legend upper assembly

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. These two components complete the upper component set alongside the upper assembly, barrel, and handguard.

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 upper.

Follow safe handling and manufacturer instructions. Ensure compliance with all applicable federal, state, and local laws.