AR9 4.5" 9mm 9×19 1:10 1/2×36 Barrel 416 Stainless Steel Plum

If you’re building a compact AR-9 pistol or looking to upgrade your existing 9mm AR platform, the AR9 4.5″ barrel is a critical component for reliable performance. This barrel is machined from 416 stainless steel and finished in a durable Plum color, offering a distinct look alongside functional precision. It’s designed for shooters who demand a quality barrel for close-quarters use or a highly maneuverable personal defense firearm, with the fast shipping from Miami Shooters Supply ensuring you get your parts without delay.

Key Features

• 4.5-inch length optimized for ultra-compact 9mm AR pistol builds.
• Chambered in 9mm Luger (9×19) for common, affordable ammunition.
• 1:10 twist rate engineered to stabilize a wide range of 9mm bullet weights.
• 416 stainless steel construction provides excellent corrosion resistance and durability.
• 1/2×36 thread pitch allows for direct attachment of common 9mm muzzle devices.
• Unique Plum finish offers a distinctive aesthetic that sets your build apart.

Built For

This barrel is ideal for the builder assembling a dedicated, short-barreled AR-9 for home defense or recreational shooting where a small footprint is key. It’s also a perfect fit for anyone creating a lightweight, truck, or travel pistol that benefits from the softer recoil and lower cost of 9mm.

Specifications

• Caliber: 9mm Luger (9×19)
• Material: 416 Stainless Steel
• Barrel Length: 4.5 inches
• Twist Rate: 1:10
• Thread Pitch: 1/2×36
• Finish: Plum
• Compatibility: Designed for AR-9 platforms with standard barrel nuts.

FAQ

Will this barrel work with my Glock magazine-fed AR-9 lower?
Yes, this AR-15 parts barrel is designed for the AR-9 platform and is compatible with builds using Glock-style, Colt-style, or other common 9mm lower receivers. Always confirm your upper receiver’s compatibility.

What type of muzzle device can I use?
The 1/2×36 thread is a standard pitch for many 9mm compensators, flash hiders, and linear compensators. You can also use a 1/2×36 to 1/2×28 adapter if you have a .223/5.56 device you prefer, though direct-thread is always recommended.