A magazine 'plug'Inserted into a tubular magazine, used to limit the amount of shells a magazine can hold. is usually made of wood or plastic and is inserted in the tubular magazine to limit the number of shells a shotgun may hold. Federal law requires that the shotgun be limited to a capacity of three (3) shells (one in the chamberPart of a firearm where ammunition is loaded and ready to be fired. and two in the magazine) while hunting any type of migratory birdsBirds that migrate southward for the winter. Includes ducks, geese, doves, etc. including doves and waterfowlBird that lives on and near the water. (example - ducks and geese).