M1819 Hall rifle The M1819 Hall rifle was a single - shot breech loading rifle designed by John Hancock Hall , patented on May 21 , 1811 , and adopted by the U . S . Army in 1819 . It was preceded by the Harpers Ferry Model 1803 . It used a pivoting chamber breech design and was made with either flint - lock or percussion cap ignition systems . The main years of production were from the 1820s to the 1830s at the Harpers Ferry Arsenal . This was the first breech loading rifle to be adopted in large numbers by any nation ' s army , but not the first breech loading military rifle - the Ferguson rifle was used briefly by the British Army in the American Revolutionary War . Breech loading rifles remained overshadowed by common musket s and muzzle loading rifles so prevalent in the early 19th century . The early flintlocks were mostly converted to percussion ignition . Comparative trials . United States Army inspectors conducted trials by having a 38 - man infantry company fire at a target for ten minutes at their own speed . Production history . The original flintlock model had a 32 . 5 inch barrel rifled with 16 " clockwise " ( right - hand ) grooves making a turn in 96 inches . The muzzle was reamed to a depth of 1 . 5 inches and had an appearance of a smooth bore . Overall length was 52 . 5 inches and weight without bayonet was 10 . 25 pounds . The rifle fired a . 525 ball weighing 220 grains ( one - half ounce ) , using a 100 - grain powder charge and 10 grains of fine powder primer . The carbine design was produced beginning in 1833 , using a smooth - bore barrel of 23 inches in length . It had an overall length of 43 inches , weighed 8 lbs , and was the first caplock firearm adopted by the U . S . Army . The following year , a carbine in . 69 caliber was introduced for the Regiment of Dragoons , with a second run in 1836 - 1837 . Barrel length was reduced to 21 inches in 1840 , and a " fishtail " breech lever design credited to U . S . Army Captain James Huger was also introduced for the next 7 , 000 carbines , including the M1842 carbine , the final " regulation design " of the series . In 1843 the Hall - North carbine , variously known as the M1843 and the " improved 1840 " , featured a side - mounted Henry North - Edward Savage breech lever . 11 , 000 Hall - North carbines were manufactured with a 21 - inch , . 52 caliber barrel . The Hall production line at Harper ' s Ferry closed in 1844 , but between 1843 and 1846 , 3 , 000 M1843 carbines were also manufactured by Simeon North . Action . The back several inches of the " barrel " ( the chamber ) is a separate piece that pivots upwards from the front for reloading . In essence the weapon was still loaded front to back , but in a short section , similar in concept to loading a cylinder of an early cap and ball revolver . The development was primarily the work of Hall , who had been working on a design in the first two decades of the 19th century , receiving critical patents during the time . The work caught the interest of Army , which lead to the contract at the end of the latter decade . The breech loading design was made possible by his focus on using carefully machined components to form a seal , but still allowing enough tolerance for the breech to be opened easily . The Hall rifle offered a significant increase in rate of fire over muzzle - loading rifles and muskets . However the design suffered from a gas leak around the interface of the removable chamber and the bore , resulting in the necessity of a heavier powder charge that still produced much less muzzle velocity than its muzzle - loading competition . No serious efforts were made to develop a seal to reduce the loss of gas from the breech . The penetrating ability of its . 52 - caliber ball for the rifle was only one - third of that of the muzzle - loaders , and the muzzle velocity of the carbine was 25 percent lower than that of the Jenks " Mule Ear " carbine despite having similar barrel lengths and identical 70 - grain powder charges . Thousands of rifles were made , though the troops and many leaders preferred the simplicity and lower costs of muzzle loaded weapons . However , the advantages were clear , and breech loading designs would grow to dominate rifle procurement after the Civil War . Many of the lessons learned by Hall would benefit designers of the next generation of breech loaders such as the Sharps rifle ( 1848 ) , Spencer carbine ( 1860 ) and others . The Halls were used against Indians and in smaller conflicts . Some saw service in the Civil War ; however , by this time many rifles were worn out over 30 years of use . As part of the process , Hall built his own shops and machinery at Harper ' s Ferry , and along with inventing this weapon , he invented many machines paving the way for uniform manufacturing of weapons with interchangeable parts . The ruins of his shops are still visible today .