Ghost Firearms AR-15 M4 20" 1:8 5.56 Barrel 

• 4150 Steel
• M4 Contour Profile
• M4 Feed Ramps
• 5.56/.223 Chambered in 5.56x45mm
• Markings Spiral Engraved Near Break
• Rifle Length Gas System 
• 1:8 Twist
• .750 Gas Platform System
• Black Nitride Coating
• 1/2 by 28 Thread