The Radical Firearms 10.5" M4 Profile 5.56mm AR Pistol uses MIL-STD Upper and lower receivers along with a 10" RPR free float rail system for increased accuracy, keeping your hands cool, and giving you plenty of room for accessories. 

Specifications 

• Barrel Length: 10.5"
• Barrel Material: 4140 Chrome Moly Vanadium
• Barrel Finish: Melonite
• Barrel Profile: M4
• Barrel Thread Pitch: 1/2X28
• Chamber: 5.56mm
• Twist Rate: 1:7
• Barrel Extension: M4 Feed Ramps
• Gas System: Carbine Length
• Gas Block Type: .750 Low Profile Gas Block
• Muzzle Device: A2 Flash Hider
• Upper Receiver Material: Forged 7075 T6
• Upper Receiver Style: M4 MIL-STD
• Upper Receiver Finish: Type III Anodizing
• Forward Assist: MIL-STD
• Dust Cover: MIL-STD
• Handguard Type: Free Float
• Handguard Style: M-Lok Thin Rail
• Handguard Length: 10"
• Charging Handle: MIL-STD
• Lower Receiver: Forged 7075 T6
• Lower Receiver Finish: Type III Anodizing
• Safety: MIL-STD STYLE AMBI
• Fire Control Group: MIL-STD
• Buffer Tube: Carbine Buffer Tube
• Pistol Brace: SB-TACTICAL SBA3
• Magazine: 5.56 30 Round