Caliber: .450 Bushmaster - Type: Pistol - Action: Semi-Automatic Gas Impingement System - Capacity: 5 + 1 Ships with one 5 Round Magazine - Safety: Manual Lever with Indicator Markings on Both Sides of Receiver - Receiver: Flat Top Upper Receiver / Magpul Enhanced Trigger Guard in Lower - Receiver Material: Forged 7075 T6 Aircraft Aluminum with Aluminum Trigger Guard - Receiver Finish: Hardcoat Black Anodize Finish with Laser Caliber Identification - Bolt Material: Carpenter 158 Steel - Barrel: 9 Medium Profile Melonite QPQ Finish with .450 Compensator - Barrel Material: 4150 Chrome Moly Vanadium 11595E Steel w. M4 Feed Ramps - Rifling: 1 Turn in 24 Right Hand Twist - Receiver Tube: Fitted with SB Tactical Pistol Arm Brace Includes a Q.D. Endplate and Q.D. sling swivel - Forend: 7 Windham Weaponry Free-Float Railed Handguard - Pistol Grip: Hogue Beavertail Pistol Grip - Rear Sight: Magpul MBUS Rear Flip Sight - Front Sight: Magpul MBUS Front Flip Sight - Packaging: Hard Plastic Gun Case with Operators Manual