This may affect other weapons but I have only tested it on the blaze. When you manually remove the snap loader from the blaze (drag and drop) into an empty inventory space and then reload the weapon using "r". The snap loader will be both in the gun and inside your inventory. If you try to swap something else in the inventory with the "ghost snap loader" in the inventory, you can't. If you move the "inventory ghost snap loader" it pulls the snap loader from your gun.

You can get a few of these in your inventory by repeating the process several times. They are essentially dead inventory space. A relog fixes the issue.