Davidson Defense Aegis w/Gauntlet Arms Brace 5-inch 1:10 9MM AR-9 M-Lok Handguard Pistol Full Build Kit

Aegis w/Gauntlet Arms Brace 5-inch 9mm AR-9 Full Build Kit

The Aegis w/Gauntlet Arms Brace is a 5-inch 9mm AR-9 Full Build Kit built around a BC-9 PCC barrel and a 7075-T6 aluminum upper receiver. It pairs a 4-inch ultra-lightweight minimalist handguard with a Design 11 Flash Can, Revision 2 Pattern 2 muzzle device, giving this build a compact, front-light profile. A 9mm nitride bolt carrier group, Mil-Spec charging handle, complete Lower Parts Kit, pistol-caliber buffer-system components, and a Gauntlet Arms polymer stabilizing brace round out the rest of the build.

Key Features

• BC-9 PCC 5-inch 9mm barrel, 1:10 twist, slim profile
• 7075-T6 aluminum upper receiver with M4 feed ramps
• 4-inch ultra-lightweight minimalist K-style free-float handguard
• Design 11 Flash Can, Revision 2 Pattern 2, steel with black oxide finish
• 9mm nitride bolt carrier group with external extractor, Glock and Colt-pattern magazine compatibility
• Gauntlet Arms polymer stabilizing brace included
• Complete Mil-Spec Lower Parts Kit and pistol-caliber buffer-system components included

Barrel and Muzzle Device

The barrel is a BC-9 PCC model, running 5 inches long, chambered in 9mm and finished in Parkerized, cut to a slim profile. It carries a 1:10 twist rate with a 1/2x36 muzzle thread. At the muzzle sits a Design 11 Flash Can, Revision 2 Pattern 2, machined from steel with a black oxide finish and threaded to match the barrel's 1/2x36 pattern, secured with the included 1/2-inch black crush washer.

Upper Receiver and Handguard

The upper receiver is machined from 7075-T6 aluminum with an anodized finish, cut with M4 feed ramps for smooth feeding and fitted with a standard 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 4-inch handguard in a K-style, ultra-lightweight minimalist profile, keeping this compact build slim and light up front. It's M-LOK compatible along its length, though it skips anti-rotation tabs, relying on its mounting hardware alone to stay indexed.

Bolt Carrier Group and Charging Handle

The bolt carrier group is a 9mm nitride unit machined from 8620 alloy steel, fitted with an external extractor for reliable case ejection. It's built for Glock and Colt-pattern magazine compatibility, giving the buyer flexibility depending on the lower this build eventually pairs with. 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 is included, covering the fire-control and lower-control internals needed once a lower receiver is on hand. Behind it sits a heavy-duty pistol buffer tube compatible with AR-15 and AR-style pistols, holding an AR-15 9mm carbine buffer and a standard USA-made recoil spring. A standard castle nut and Mil-Spec AR-15/M16 receiver end plate secure the buffer tube assembly to the lower.

Stabilizing Brace

Capping off the rear of the build is a Gauntlet Arms polymer stabilizing brace finished in black. It mounts directly to the pistol buffer tube included with this kit, built specifically for pistol-configured AR platforms like this 9mm build.

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