Isn't the word "shotgun" a self-redundancy? [closed]
The "shot" in shotgun refers to the ammunition that the gun fires. Whereas a pistol or rifle fires bullets (single metal balls), a shotgun fires a shell packed with shot (hundreds of tiny metal balls).
There are other things that shoot 'shot'. Cannons fired grapeshot as an effective way to deal with infantry. This makes a 'shotgun' just a gun that shoots shot instead of a cannon that does so. This clever naming scheme is also visible for 'rifles' which are simply guns with barrels that have been rifled.