Puckle gun The Puckle gun ( also known as the " Defence gun " ) was a primitive autocannon invented in 1718 by James Puckle ( 1667 – 1724 ) a British inventor , lawyer and writer . The Puckle gun mechanism was essentially a flintlock revolver ; the design concept behind the Puckle gun turned out to be years ahead of what was technologically achievable with 18th century technology . The first practical guns using this design principle , now known as revolver cannon s , only appeared in the mid - 1940s . Design and patent . It is a tripod - mounted , single - barreled flintlock weapon fitted with a multishot revolving cylinder . It was intended for shipboard use to prevent boarding . The barrel was long with a bore of . It had a pre - loaded cylinder which held 11 charges . It was thus a manually operated ( thus externally powered ) machine cannon . According to the Patent Office of the United Kingdom , " In the reign of Queen Anne of Great Britain , the law officers of the Crown established as a condition of patent that the inventor must in writing describe the invention and the manner in which it works . " This gun ' s patent was one of the first to provide such a description . One modern author remarked however that " James Puckle ' s patent in 1718 contains more rhetorical fervor than technical rigor . " Two versions . Puckle demonstrated two versions of the basic design : one , intended for use against Christian enemies , fired conventional round bullets , while the second variant , designed to be used against the Muslim Turks , fired square bullets . The square bullets were considered to be more damaging . They would , according to the patent , convince the Turks of the " benefits of Christian civilization . " The square bullets , however , were discontinued due to their unpredictable flight pattern . Production and use . Prototypes were shown in 1717 to the English Board of Ordnance , but they were " not impressed " . However , " at a public trial held in 1722 , the gun was able to fire 63 shots in seven minutes in the midst of a driving rain storm , an amazing feat for the period . " The Puckle Gun drew few investors and never achieved mass production or sales to the British armed forces . As with other designs of the time it was hampered by " clumsy and undependable flintlock ignition " and other mechanism problems . One newspaper of the period sarcastically observed , following the business venture ' s failure , that the gun has " only wounded those who hold shares therein " . John Montagu , 2nd Duke of Montagu , Master - General of the Ordnance ( 1740 - 1749 ) , purchased several for an ill - fated expedition in 1722 to capture St Lucia and St Vincent . There is no evidence that the guns were ever used in battle though . Surviving examples . Two examples are on display at former Montagu homes : One at Boughton House and another at Beaulieu Palace . There is a replica of a Puckle gun at Bucklers Hard Maritime Museum in Hampshire . Blackmore ' s " British Military Firearms 1650 – 1850 " lists " Puckle ’ s brass gun in the Tower of London " as illustration 77 . Similar guns . A single exemplar of a 2 inch bore , five - shot revolver cannon was built and used by the Confederate States of America during the Siege of Petersburg . It was captured on 27 April 1865 by Union troops and sent for examination at West Point . In popular culture . The Puckle Gun is featured in Tony Harrison ' s play " Square Rounds " . In the 2009 PC game , the Puckle Gun is available as a unit in the late 18th century . Only a limited number may be maintained at a time by a faction , reflecting the weapon ' s historical unpopularity . In the Belisarius series by Eric Flint and David Drake , the Romans mount Puckle Guns on their steamships and supply barges to protect their supply lines on the Indus River . One is used to repel boarders in the final novel " The Dance of Time " . 2000AD series " Defoe " references the Puckle Gun in the form of an elaborate clockpunk machine gun which fires " round bullets for Christians , square bullets for zombies " . The Puckle Gun is referenced in the 2007 Richard Morgan novel " Black Man " . The Puckle Gun is referenced in the 1908 George Daulton short story " The Death - Trap " .