AT3™ 22LR 4.5″ Barrel Kit – Complete Dedicated 22LR Conversion with BCG and Magazine
Features
- 4.5-inch tapered profile barrel for ultra-compact builds
- 4150 CrMoV steel with black nitride finish
- 1:16 twist rate optimized for standard 22LR loads
- 1/2×28 muzzle threads accept standard AR-15 muzzle devices
- Dedicated 22LR stainless steel bolt carrier group included
- 25-round Black Dog Machine magazine included
- Complete kit ready for installation
This complete barrel kit delivers everything you need to build an ultra-compact dedicated 22LR upper for your AR-15. The 4.5-inch tapered barrel is purpose-built for the most compact PDW-style pistol builds, suppressor hosts, or backpack guns where every inch counts but you still want the affordable ammunition and low recoil of 22LR. This kit includes the barrel, a dedicated stainless steel 22LR bolt carrier group, and a 25-round Black Dog Machine magazine—everything you need except the upper receiver, handguard, and muzzle device.
The AT3 4.5-inch barrel is crafted from premium 4150 CrMoV steel per MIL-B-11595E specs with black nitride finish for durability and corrosion resistance. The tapered profile keeps weight down while maintaining accuracy with 22LR ammunition, and the 1:16 twist rate is optimized for standard 22LR loads. At just 4.5 inches long with 1/2×28 muzzle threads, this is the most compact 22LR barrel option available.
The included AT3 stainless steel 22LR bolt carrier group is machined to exact tolerances for reliable cycling with 22LR ammunition. Designed specifically for use with AT3 22LR barrels and Black Dog Machine magazines, this BCG delivers consistent performance in dedicated 22LR builds. The 25-round Black Dog Machine magazine features innovative sonic-welded polymer construction for durability and lightweight performance. This kit gives you everything you need to experience the joy of ultra-compact 22LR shooting.
Specifications
- Brand: AT3 Tactical
- Model: 22LR 4.5″ Barrel Kit – 4.5″ Tapered 22LR Barrel – Dedicated 22LR BCG – 25rd Black Dog 22LR Magazine
- MPN: AT3-22-BBL-KIT-BCG-BDM-45
- Caliber: 22LR
- Barrel Length: 4.5 inches
- Barrel Profile: Tapered
- Barrel Material: 4150 CrMoV Steel
- Barrel Finish: Black nitride
- Barrel Twist: 1:16
- Muzzle Thread: 1/2×28
- BCG Material: Stainless steel
- Magazine Capacity: 25 rounds
- Magazine Material: Polymer
- Color: Black













