Properly loading a Mossberg .410, pump-action shotgun is a crucial component of safe shooting. Inspect the Mossberg's magazine tube, tang, magazine loading port, ejection port and barrel chamber to ensure each is in proper working condition. This will help prevent misfires, jams and phantom rounds, all of which might lead to accidents. Loading the Mossberg is synonymous with inspecting the shotgun's mechanical parts.
Pick up the Mossberg with the barrel pointed away from your body. Click the safety -- located at the back of the trigger guard -- to the "on" position. Depress the action-bar lock located at the front of the trigger guard. Pull the forestock toward the trigger guard until the ejection port is completely open. You will hear a click when the ejection port is completely open.
Look through the ejection port into the Mossberg's chamber. Make certain a phantom round -- a shell that failed to eject -- is not lodged in the chamber. Press down on the carrier and look into the magazine tube. Make certain there is not a round jammed in the magazine.
Place a shell between your forefinger and middle finger; press your thumb against the shell's primer. With the nose of the shell, press down on the carrier and slide the shell into the magazine tube. Push the shell into the tube -- using your thumb -- until the rim of the brass head slides past the tang. Use this method to load the desired number of shells into the magazine.
Depress the action-bar lock. Assertively pull the forestock toward the trigger guard until the ejection port is completely open. Push the forestock back into place, thereby loading a round into the chamber and closing the ejection port. Slowly or weakly chambering a round increases the odds of a jam or misfire. Chamber rounds aggressively. Your Mossberg .410 is now magazine-loaded with a chambered round. Depress the safety and you are ready to fire.