Davidson Defense Three Hundo 16-inch AR-15 .300 BLK Rifle Upper Build Kit

Three Hundo 16 Inch AR-15 Upper Build Kit .300 Blackout Freefloat Quad Rail

The Three Hundo AR-15 Upper Build Kit is an upper assembly package built around a 16 inch 4150 Chrome Moly Vanadium barrel with a Phosphate finish, HBAR profile, and a 1:8 twist rate for .300 Blackout. The upper receiver is machined from 7075-T6 aluminum with an anodized finish, paired with a 15 inch freefloat quad rail handguard made from aircraft-grade aluminum in black. This kit covers the upper receiver, barrel, and handguard as the core front end components of an AR-15 rifle build. BCG and charging handle are not included.

Key Features

• 16 inch 4150 CMV barrel, Phosphate finish, HBAR profile
• 1:8 twist rate, 5/8x24 thread pitch
• Pistol length gas system
• Gas block size 0.75
• 7075-T6 aluminum upper receiver, anodized finish
• 15 inch freefloat quad rail handguard, aircraft-grade aluminum, black
• GI birdcage flash hider
• BCG and charging handle not included

Perfect For

• Builders who already have a bolt carrier group and charging handle on hand
• Shooters wanting a .300 Blackout platform with a freefloat quad rail handguard
• Builders looking to complete the upper side of an AR-15 rifle without duplicating parts they already own

Barrel and Gas System

This kit uses a 16 inch barrel made from 4150 Chrome Moly Vanadium with a Phosphate finish and an HBAR profile. The 1:8 twist rate is suited to a wide range of .300 Blackout bullet weights, and the 5/8x24 thread pitch matches the included GI birdcage flash hider. A pistol length gas system runs to a gas block sized at 0.75. The barrel and gas components make up the front end of this upper build kit.

Upper Receiver and Handguard

The upper receiver is machined from 7075-T6 aluminum and finished with a durable anodized coating. A 15 inch freefloat quad rail handguard made from aircraft-grade aluminum in black surrounds the barrel without contacting it, completing the exterior forend included in this kit.

Follow safe handling and manufacturer instructions.

Ensure compliance with all applicable federal, state, and local laws.

BCG and charging handle are not included.

Component specifications are subject to the details provided in this listing.