New arrival at HitGuns.com... "Here at HitGuns.com, we have just received a new gun, the Full Metal Body M4A1 with Hop-Up System (BI-3681). BI 3681 is Boyi's M4 series latest product (as of 2007 July). It is an exact replica of AR-15, a US military used Assault Rifle. The uniqueness of BI 3681 is its body is full metal, included barrel, upper and lower receiver. It also carries 7mm Bushing and V2 metal gear box. This item can shoot 310-330 fps stock, and it is upgradeable to higher velocity."

Features

• Weight: 11 lbs with box
• Power: 300-330fps with 0.2g BB
• Metal Gear box: Yes
• Adjustable Hop up: Yes
• TM compatible Hop up: Yes
• Hi-Capacity Magazine: Included
• Battery and Charger: Included
• 7mm smooth gear box, fibre grip and heat sink motor plate