The above 
                  described method is common to most airsoft gas guns. Has 
                  disadvantages such as the need for taking a bottle or 
                  problematic firing at lower temperatures. A huge plus is 
                  realistic weapon functions. These, mostly metal, replicas have 
                  internal trigger mechanism very similar to the real one. The 
                  gun has a real field take down, require cleaning and 
                  lubricating. When you insert magazine, you have to pull 
                  receiver and load first BB from the magazine to the chamber. 
                  For each shot there is a subsequent 'kick' back and reloading. 
                  The gun can shot semi or full auto. It provides great metal 
                  clicking sound and mild recoil. After shot out all bullets 
                  from the magazine (which usually has a more or less real 
                  capacity), the receiver remain as a real weapon in the back 
                  position.
                  This 
                  presented gun works as has been described above. The body is 
                  manufactured on CNC machined from a block of aluminum alloys. 
                  The barrel is (to increase the weight) made of steel. Many 
                  parts are obviously taken from real weapon. Sights, pistol 
                  grip, stock, receiver cap...etc. The selector switch works 
                  exactly as a real weapon.