Swivel gun The term swivel gun usually refers to a small cannon , mounted on a swiveling stand or fork which allows a very wide arc of movement . Another type of firearm referred to as a swivel gun was an early flintlock combination gun with two barrels that rotated along their axes to allow the shooter to switch between rifled and smoothbore barrels . Swivel guns should not be confused with pivot gun s , which were far larger weapons mounted on a horizontal pivot , or screw gun s , which are a mountain gun with a segmented barrel . An older term for the type is " peterero " ( alternative spellings include " paterero " and " pederero " ) . The name was taken from the Spanish word for " stone " ( pedrero ) , because it was the first type of ammunition fired . Configuration . Swivel guns are among the smallest types of cannon , typically measuring less than 1 m ( 3 ft ) in length and with a bore diameter of up to 3 . 5 cm ( 1¼ in ) . They can fire a variety of ammunition but were generally used to fire grapeshot and similar types of small - diameter shot , though they could also fire small caliber round shot . Most swivel guns were muzzleloader s . They were aimed through the use of a wooden handle , somewhat similar in shape to a baseball bat , attached to the breech of the weapon . Some swivel guns were designed as breech - loading swivel gun s as early as the 16th century , making them among the first such examples of this type of weapon . Breech - loading swivel guns had a breech shaped like a beer mug , which the gunner would take by the handle and insert into the body of the swivel gun with the breech ' s opening facing forwards . The gunpowder and projectiles were loaded into the breech before it was inserted into the gun . If a number of breeches were prepared beforehand , the gunner could maintain a high rate of fire for a brief period simply by swapping out the used breech and replacing it with a freshly loaded one . Applications . Swivel guns were used principally aboard sailing ships , serving as short - range anti - personnel ordnance . They were not ship - sinking weapons , due to their small caliber and short range , but could do considerable damage to anyone caught in their line of fire . Due to their relatively small size , swivel guns were highly portable and could be moved around the deck of a ship quite easily ( and certainly much more easily than other types of cannon ) . They could be mounted on the deck railings of a ship , which provided the gunner with a reasonably steady platform from which to fire . Their portability enabled them to be installed wherever they were most needed ; whereas larger cannon were useless if they were on the wrong side of the ship , swivel guns could be carried across the deck to face the enemy . The small size of swivel guns enabled them to be used by a wide variety of vessels , including those too small to accommodate larger cannons , and also permitted their use on land ; they were commonly issued to forts in North America in the 18th century , and Lewis and Clark took one with them on their famous expedition into the American interior in 1804 . Swivel guns also had peaceful uses . They were used for signalling purposes and for firing salutes , and also found uses in whaling , where bow - mounted swivel guns were used to fire harpoon s , and fowling , where swivel guns mounted on punts were used to shoot flocks of waterfowl ( see also punt gun ) . Swivel guns were extensively used by the kingdoms and empires of Asia , particularly China and Korea . The first Chinese swivel guns were cast as early as 1520 after being introduced from Europe , and Korea followed suit by the 1560s . During the Japanese invasions of Korea ( 1592 – 1598 ) , Korean naval forces used swivel guns and larger cannon to great effect in interdicting the invading Japanese forces . External links . fr : pierrier ru : pierrier vi : pierrier