Davidson Defense Quadratic 20-inch Rifle-Gas 1:7 22 ARC AR-15 Quad-Rail Handguard Rifle Full Build Kit

Quadratic 20-inch Rifle-Gas 1:7 22 ARC AR-15 Quad-Rail Handguard Rifle Full Build Kit

This is a complete 22 ARC AR-15 build kit designed for shooters who want a precision rifle platform without the assembly hassle. You get a 20-inch nitride barrel with a 1:7 twist rate, free-float quad-rail handguard, and all the components needed to complete a lower receiver. Everything here is mil-spec compatible and ready to build.

Key Features

• 20-inch Bear Creek Arsenal nitride barrel with 1:7 twist rate for .22 ARC precision
• Free-float quad-rail handguard with full-length four-sided Picatinny rails for accessory mounting
• Complete lower parts kit with mil-spec fire control group and trigger assembly
• AR-15 6.5 Grendel II bolt carrier group with QPQ nitride finish
• SOPMOD-style collapsible stock with integrated storage and QD sling mounts
• Micro low-profile gas block paired with rifle-length gas system
• GI A2 birdcage flash hider with crush washer included

Perfect For

• Shooters building a precision .22 ARC rifle platform
• Hunters seeking a lighter-recoiling mid-range cartridge option
• Builders who want a complete upper and lower component set
• Marksmen using quad-rail systems for optics and accessory integration

22 ARC Platform and Precision Focus

The .22 ARC cartridge sits between .223 Remington and 6.5 Grendel in terms of velocity and energy. This kit pairs that cartridge with a 20-inch barrel and 1:7 twist rate optimized for heavier projectiles in the .22 ARC range. The free-float handguard isolates the barrel from the upper receiver, reducing vibration and improving consistency shot to shot. Quad-rail systems give you complete flexibility for mounting optics, lights, and other accessories without rail-specific limitations.

Complete Lower and Upper Assembly

This kit includes the upper assembly with barrel and handguard, plus a complete lower parts kit with fire control group, trigger assembly, and all springs and pins needed to finish a stripped lower receiver. The SOPMOD-style stock includes storage compartments and QD sling attachment points. The 6-position buffer tube gives you length-of-pull adjustment from 10.5 to 12.5 inches depending on your shooting position and body type.

Nitride Finish and Durability

The. Bear. Creek. Arsenal barrel features a black nitride finish that resists corrosion and reduces friction during cycling. The QPQ nitride bolt carrier group uses the same process for long-term reliability. Both finishes are designed to handle regular shooting and field use without excessive maintenance.

Micro Gas Block and Rifle-Length System

The micro low-profile gas block sits low on the barrel to maintain sight line clearance. Paired with the rifle-length gas tube, this system balances cycling speed with controllability. The .750-inch gas journal diameter is standard for rifle-length systems and pairs with the included gas block without modification.

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