Robert Adams ( handgun designer ) Robert Adams ( 1809 – 1880 ) was a 19th - century British gunsmith who patented the first successful double - action revolver in 1851 . His revolvers were used during the Crimean War , the Indian Mutiny , the U . S . Civil War , and the Anglo - Zulu War . Career . Dean and Adams . Adams was the manager for the London arms manufacturers George & John Deane . On August 22 , 1851 , he was granted a British patent for a new revolver design . The . 436 Dean and Adams was a five - shot percussion ( cap - and - ball ) revolver with a spurless hammer , and the first revolver with a solid frame . The revolver used a double - action only system in which the external hammer could not be cocked by thumbing it back , like most other pistols of the era , but instead cocked itself when the trigger was pulled . This made it possible to fire the gun much more rapidly than contemporary single - action revolvers , such as the Colt , which had to be cocked prior to each shot . The Dean and Adams revolver was shown at the Great Exhibition of 1851 and subsequently approved by the British Army ' s Small Arms Committee in addition to being adopted by the East India Company for use by their cavalry . Orders for the revolver were great enough to prompt the Deane brothers to make Adams a partner in their firm , which became Messrs . Deane , Adams , and Deane . Although highly regarded , the hand - crafted Adams revolver was more expensive than Colt ' s mass - produced guns . It also lacked a recoil shield behind the cylinder , which left the shooter ' s hand subject to powder burns resulting from " blowback " caused by the sometimes unpredictable black powder of the era . The lack of a hammer spur was also criticized since the longer trigger pull of the Adams made it less accurate than the Colt . Furthermore , the Adams ' nipples , upon which the percussion caps were set , were unhardened and sometimes burst upon firing . An " Improved Frame " model was offered in 1854 , presenting both a sleeker look and more comfortable grip . In that same year the British Board of Ordnance reviewed the Adams together with other percussion revolvers with a view to adopting one as an official service sidearm . Concerns about the gas escape between the cylinder and barrel during discharge resulted in no decision being made . Nevertheless , British officers purchased the Adams privately and the gun proved its worth in battle during the Crimean War . Beaumont - Adams . In 1855 a veteran of the Crimean conflict , Lieutenant Frederick E . B . Beaumont , improved the gun by linking the trigger to a spurred hammer , permitting both single - and double - action fire . A new version of the revolver , the Beaumont - Adams , was produced and became so popular that it is said Samuel Colt was forced to shut down his London manufactory as a result . London Armoury Company . Adams had a falling out with the Deane brothers the following year and founded a new arms concern , the London Armoury Company , on February 9 , 1856 . Another important stockholder was Adams ' cousin , James Kerr , who later invented the Kerrs Patent Revolver . The factory was established on the former site of the South - Eastern Railway Company in the Bermondsey section of London . The Indian Mutiny of 1857 established the Adams as the official revolver of the British Army . In the bitter fighting it was found that rapid fire was more important than accuracy , and the man - stopping power of the Adams ' large caliber bullet was also valued . Several variations and improvements were made upon the Adams , which was manufactured in Europe and briefly in the United States under license . The majority of British - made Adams guns seem to have been in 54 bore ( approximately . 44 caliber ) , but several smaller and at least one larger bore were also offered . In 1857 the U . S . government purchased 100 revolvers in . 36 caliber and another 500 from the Adams - licensed Massachusetts Arms Company . The 100 British - made guns were issued to the U . S . Army with the rest held in storage until issued at the outbreak of the U . S . Civil War . In addition Adams revolvers were purchased from the London Armoury prior to and during the war by individual states and the U . S . and Confederate governments . The London Armoury Company flourished due to the manufacture of the Adams revolver , however , in 1859 the company ' s board of directors decided to increase the production of infantry rifle s , decreasing revolver production . Adams disagreed with the decision , selling his stock and leaving the company . Kerr then became the armoury ' s dominant figure and his revolver , together with a large number of rifles , were sold to the Confederate government which became the armoury ' s principal client . With the fall of the Confederacy the fortunes of the company declined and it went into receivership in 1866 . Adams owned the rights to his revolver , which the London Armoury Company had only produced under license , and he now manufactured them in Birmingham , with minor improvements keeping his revolvers in competition with other designs . John Adams . In 1867 , Robert Adams ' brother John Adams patented a breech - loading revolver which was adopted by the British government in place of the Beaumont - Adams . It was a solid frame pistol with six chambers , in . 450 caliber . After official acceptance of his pistol , Adams left the London Armoury Company and established his own factory , the Adams Patent Small Arms Company . His pistol was manufactured in three distinct variations ( differences related mainly to methods of spent cartridge ejection ) between 1867 and about 1880 . The models were tested and adopted by the British Army and Navy , with the last , the M1872 Mark III , seeing the widest use . The John Adams revolver remained the official sidearm of the British Army until replaced by the Enfield Mark I in 1880 .