The Lead & Steel L&S LS9MM45-36 4.5 AR9 Nitride Barrel is purpose-built for 9mm AR-pattern pistols, offering a compact 4.5 inch threaded barrel for shooters who want a reliable, modern upgrade. Marked "9MM 1/10 4150 4.5" on the barrel, it uses a 1:10 twist and 4150 steel to support consistent performance with common 9mm loads.

This short AR9 barrel is well suited for range use, training, and building compact pistol-caliber carbines where maneuverability and balance matter. The threaded muzzle makes it easy to add compatible devices such as muzzle brakes or suppressor mounts, while the nitride treatment is designed to enhance durability and corrosion resistance. It reflects Lead & Steel’s focus on practical design and solid craftsmanship for dedicated AR builders.

Key Features:

• Manufacturer: Lead & Steel
• Model: AR9
• Caliber: 9mm
• Barrel Length: 4.5"
• Twist Rate: 1:10
• Barrel Material: 4150 steel
• Threaded Barrel: Yes
• Length: 5.50" overall