Davidson Defense ARCitect 20-inch Rifle-Gas 1:7 22 ARC AR-15 KeyMod Handguard Rifle Full Build Kit

ARCitect 20-inch .22 ARC AR-15 Full Build Kit

The ARCitect is a Full Build Kit built around a 20-inch heavy .22 ARC barrel, built from 4150 chrome moly vanadium steel with a Parkerized finish, paired with a 7075-T6 aluminum upper receiver finished in black anodizing. It pairs a Trinity Force ECHO 15-inch KeyMod rail handguard with an AR-15 A2 GI birdcage flash hider at the muzzle, running on a rifle-length gas system. A 6.5 Grendel II bolt carrier group, Mil-Spec charging handle, complete Lower Parts Kit, carbine buffer-system components, and a SOPMOD-style collapsible stock round out the rest of the rifle. The lower receiver is not included, leaving the buyer to select and supply that component separately.

Key Features

• 20-inch heavy .22 ARC barrel, 1:7 twist, Parkerized finish
• Rifle-length gas system with micro low-profile steel gas block
• 7075-T6 aluminum upper receiver, black anodized finish
• Trinity Force ECHO 15-inch KeyMod rail handguard
• AR-15 A2 GI birdcage flash hider, 5.56 NATO/.223 Remington compatible
• 6.5 Grendel II bolt carrier group, QPQ nitride finish
• SOPMOD-style collapsible stock with integrated QD mounts and dual storage compartments
• Complete Mil-Spec Lower Parts Kit and carbine buffer-system components included
• Lower receiver is not included.

Barrel and Gas System

The barrel runs 20 inches long, chambered in .22 ARC and built from 4150 chrome moly vanadium steel with a Parkerized finish and heavy profile. It carries a 1:7 twist rate and a 1/2x28 muzzle thread. Gas cycles back to the action through a rifle-length system, running a stainless steel rifle-length gas tube and a micro low-profile steel gas block sized to a .750-inch journal.

Upper Receiver and Handguard

The upper receiver is machined from 7075-T6 aluminum and finished in black anodizing, cut with M4 feed ramps for smooth feeding and fitted with an AR-15 forward assist assembly. The ejection port carries a standard .223/5.56 door with its rod and spring installed. Over the barrel sits a Trinity Force ECHO 15-inch handguard, using a KeyMod attachment system along its length.

Muzzle Device

Capping the muzzle is an AR-15 A2 GI birdcage flash hider, compatible with both 5.56 NATO and .223 Remington. It threads onto the barrel's 1/2x28 pattern and is secured with the included 1/2-inch black crush washer.

Bolt Carrier Group and Charging Handle

An AR-15 6.5 Grendel II bolt carrier group is included, finished in QPQ nitride. That listed compatibility describes the BCG itself; the barrel and chambering on this build remain .22 ARC. A Mil-Spec AR-15 M4 charging handle rounds out the upper's operating components.

Lower Parts Kit and Buffer System

A complete Mil-Spec AR-15 Lower Parts Kit covers the fire-control and lower-control internals needed once a lower receiver is on hand. Behind it sits a Mil-Spec heavy-duty six-position buffer tube, holding a standard AR-15 carbine buffer weighing 3 ounces and a standard USA-made recoil spring. An AR-15 carbine castle nut and Mil-Spec AR-15/M16 receiver end plate secure the buffer tube assembly to the lower.

Stock

Capping off the rifle is a SOPMOD-style collapsible stock finished in black, featuring integrated QD sling mounts and dual storage compartments. It slides onto the six-position buffer tube included with this kit, giving the shooter adjustable length-of-pull for the final piece of the build.

Follow all manufacturer instructions and safe handling practices.

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

Lower receiver is not included.