Up to 20% Off AR-15 Uppers & Accessories | Shop Now

Up to 20% Off AR-15 Uppers & Accessories | Shop Now

.300 Blackout AT3 Tactical AR-15 Parts

.300 Blackout AR parts from AT3 Tactical, including made-to-order upper receivers with Ballistic Advange barrels.

Showing 1–24 of 29 results

List

Grid

Filter

Sort

LIST

Black Warhammer with BCG

(54)

AT3™ Black Nitride 5.56 Bolt Carrier Group with Breek Arms Warhammer AR-15 Charging Handle

RECOMMENDED

AT3 Tactical AT-15 M-LOK Builder Set - Lower, Upper, and SPEAR M-LOK Handguard

(9)

AT3™ AT-15 M-LOK Builder Set – Anodized and Cerakote

RECOMMENDED

AT3 Tactical AT-15 Quad Rail Builder Set - Lower, Upper, and Pro Quad Rail Handguard

(6)

AT3™ AT-15 Quad Rail Builder Set – Anodized and Cerakote

RECOMMENDED

AT3™ AR-15 Bolt Carrier Group - 5.56 NATO/.300 Blackout - Black Nitride

(195)

AT3™ AR-15 Bolt Carrier Group Black Nitride – .223/5.56 NATO .300 Blackout .350 Legend

RECOMMENDED

(17)

AT3™ AR-15 Bolt Carrier Group Nickel Boron – .223/5.56 NATO .300 Blackout .350 Legend

Spare 5.56 Bolt in Black Nitride

(9)

AT3™ AR-15 Replacement Bolt – 5.56 NATO/.300 Blackout – Black Nitride

AT3 Tactical 3-Port Muzzle Brake

(25)

AT3™ AR-15 3-Port Muzzle Brake – 5/8×24 – .300 BLK/.308 Win – Crush Washer Included

NEW

AT3 Barrel Builder Kit – 7.5″ .300 Blackout Medium Profile Pistol Length Barrel, Gas Block & Gas Tube

NEW

AT3 Barrel Builder Kit – 7.5″ .300 Blackout Medium Profile Pistol Length Barrel, Gas Block, Gas Tube & BCG

Black Upper with BCG

(11)

AT3™ Slick Side AR-15 Upper with Black Nitride 5.56 Bolt Carrier Group

Slick Side Upper with Ambi Charging Handle and Bolt Carrier Group

(2)

AT3™ Slick Side Upper with Bolt Carrier Group and Breek Arms Warhammer Charging Handle

AT3™ AR-15 A2 Mil-Spec Flash Hider with Crush Washer

(13)

AT3™ .300 BLK/.308 WIN Birdcage Flash Hider with Crush Washer

AT3 Tactical Crush Washer - 5/8 Inch for .308/7.62

(6)

AT3™ 5/8 Inch Crush Washer for .308/7.62 Muzzle Devices

AT3 Tactical AR-15 Barrel – 7.5″ – 300 Blackout – Medium Profile – Pistol Length

AT3 Tactical AR-15 Barrel – 14.5″ – .300 Blackout – Medium Profile – Pistol Length

(2)

AT3 Tactical AR-15 Barrel – 16″ – .300 Blackout – Medium Profile – Pistol Length

AT3 Tactical AR-15 Barrel – 6″ – .300 Blackout – Medium Profile – Pistol Length

AT3 Tactical Extractor for .223/5.56 Bolts - Black Nitride

(1)

AT3 Tactical Extractor for .223/5.56 Bolts – Black Nitride

AT3 Alternator AR-15 Pistol

AT3™ AT-15 ALTERNATOR Pistol 10.5 Inch .300 Blackout Barrel – 12 Inch M-LOK Handguard

AT3 Flatline AR-15 Rifle

AT3™ AT-15 FLATLINE Rifle 16 Inch .300 BLK – 15 Inch M-LOK Handguard

AT3™ .300BLK 16″ Assembled Forged Upper – 2A Basics ASAL 15" Handguard – No BCG/Charging Handle

AT3™ .300BLK 16″ Assembled Forged Upper – 2A Basics ASAL 15″ Handguard – No BCG/Charging Handle

NEW

AT3 10.5" .300 Blackout AR-15 JNL Ready Build Kit

AT3 10.5″ .300 Blackout AR-15 JNL Ready Build Kit

NEW

AT3 Barrel Builder Kit – 10.5″ .300 Blackout Medium Profile Pistol Length Barrel, Gas Block & Gas Tube

(1)

AT3 Tactical AR-15 Barrel – 10.5″ – .300 Blackout – Medium Profile – Pistol Length