Start by cutting a piece of pipe slightly longer than your hand (mine was approx 13cm), making sure to remove any burred edges.
Next we are going to add a stopper that we’re going to make from a paper clip. We’ll start by putting four small holes in one end of the pipe. You can do this by using a small drill bit or by heating up a paper clip to burn through a hole.
Put the four holes across from each other. If you slightly stagger the holes then it will accept wider ammo. Now simply feed your paper clip through the holes until it looks like mine.