If there is any question concerning a gun's ability to function, a knowledgeable gunsmith should look at it. Know how to use the gun safely. Before handling a gun, learn how it operates. Know its basic parts, how to safely open and close the action and remove any ammunition from the gun or magazine. Remember, a gun's mechanical safety device is never foolproof.
Nothing can ever replace safe gun handling.
Use only the correct ammunition for your gun. Only BBs, pellets, cartridges or shells designed for a particular gun can be fired safely in that gun. Most guns have the ammunition type stamped on the barrel. Ammunition can be identified by information printed on the box and sometimes stamped on the cartridge. Do not shoot the gun unless you know you have the proper ammunition.