Davidson Defense ARChimedes 20-inch Rifle-Gas 1:7 22 ARC AR-15 Freefloat Handguard Rifle Complete Upper Build

ARChimedes 20-inch .22 ARC AR-15 Complete Upper

The ARChimedes is built around a 20-inch heavy .22 ARC barrel, built from 4150 chrome moly vanadium steel with a Parkerized finish, paired with a 7000 Series optimized AR-15 upper receiver finished in Type III black anodizing. It pairs a 17-inch free-float M-LOK handguard with an A2 GI birdcage flash hider at the muzzle, running on a rifle-length gas system. A 6.5 Grendel II bolt carrier group and Mil-Spec charging handle round out the upper, giving the buyer everything needed on the upper side.

Key Features

• 20-inch heavy .22 ARC barrel, 1:7 twist, Parkerized finish
• Rifle-length gas system with micro low-profile steel gas block
• 7000 Series optimized AR-15 upper receiver, Type III black anodized
• 17-inch free-float M-LOK handguard with front quad rail sections and QD mounts
• A2 GI birdcage flash hider
• 6.5 Grendel II bolt carrier group, QPQ nitride finish
• Mil-Spec AR-15 M4 charging handle 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 diameter.

Upper Receiver and Handguard

The upper receiver is a 7000 Series optimized AR-15 unit finished in Type III black anodizing, featuring a dust cover pin feature. The ejection port carries a standard .223/5.56 door with its rod and spring installed. Over the barrel sits a 17-inch handguard, free-floated and using an M-LOK attachment system with front quad rail sections and front and rear QD mounts.

Muzzle Device

Capping the muzzle is an A2 GI birdcage flash hider. 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. A Mil-Spec AR-15 M4 charging handle rounds out the upper's operating components.

Follow all manufacturer instructions and safe handling practices.

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