Caliber: 5.56x45MM – Capacity 30 + 1 – Upper Rec. Material: 7075-T6 Aluminum – Upper Rec. Finish: Black Hardcoat Anodized – Lower Rec. Material: 7075-T6 Aluminum – Lower Rec. Finish: Black Hardcoat Anodized – Barrel Material: 4150 CMV – Front Sight: None Included – Barrel Finish: Manganese Phosphate – Rear Sight: None Included – Barrel Technical: 1:7RH 6 Groove Chrome Lined – Fire Mode: Semi-Automatic – Barrel Length: 16.1 in. – Trigger Type: Single Stage – Overall Length: 32-35.5 in. (81-90cm) – Grip: Government A2 Grip – Unloaded Weight: 6.5lbs – Operating System: Direct Gas Impingement Carbine – Safeties: Reversible Safety Selector – Included Accessories: 30rd Magpul® PMAG® Magazine Manual Cable Lock – Tested in the harshest environments the Colt Trooper® M4 is a modern duty-grade Colt AR-15® – M-LOK® capable handguard and Flat Top Upper Receiver are ready for the addition of Optical Sights and Accessories – Lightweight extended-length Centurion Arms handguard offers modularity for mounting accessories – The Trooper® M4 is the ideal platform for your next advanced MSR build