1- First, prepare your gun by liberating both ends and letting it air out

2- Then, with the aid of a broomstick or any other long, thin object, force the ammunition, potato or otherwise (see ammo section), down the barrel to about half way

3- Give a few seconds of continuous spray into the combustion chamber with the hair spray or other (see energy section) and quickly close it off. It is important that your close off the chamber firmly but not too tight or it will be almost impossible to remove after the blast. On the other hand, you wouldn't want the back of your gun to get shoot off before the potato.