Hawken rifle The Hawken rifle was a muzzle loading rifle built by the Hawken brothers , and used on the prairies and in the Rocky Mountains of the United States during the early frontier days . It has become synonymous with the " plains rifle " , the buffalo gun , and the fur trapper ' s gun . Developed in the 1820s , it was eventually displaced by breechloaders ( such as the Sharps rifle ) and lever - action rifles which flourished after the Civil War . The Hawken " plains rifle " was made by Jacob and Samuel Hawken , in their St . Louis , Missouri shop , which they ran from 1815 to 1858 . Their shop continued to operate and sell rifles bearing the " Hawken " name under later owners William S . Hawken , William L . Watt , and J . P . Gemmer , until Gemmer closed down the business and retired in 1915 . Samuel and Jacob were trained by their father as rifle smiths on the east coast . They moved west and opened a business in St . Louis at the beginning of the Rocky Mountain fur trade . The brothers ' claim to fame is the " plains rifles " produced by their shop . They produced what their customers needed in the west , a quality gun , light enough to carry all the time , capable of knocking down big targets at long range . They called their guns " Rocky Mountain Rifles , " reflecting their customers : fur trappers , traders and explorers . History . The earliest known record of a Hawken rifle dates to 1823 when one was made for William Henry Ashley . The Hawkens did not mass - produce their rifles but rather made each one by hand , one at a time . A number of famous men were said to have owned Hawken rifles , including : Daniel Boone , Jim Bridger , Kit Carson , Orrin Porter Rockwell , Joseph Meek , Jedediah Strong Smith , and Theodore Roosevelt . Hawken rifles had a reputation for both accuracy and long range . The Hawken rifle company was sold in 1862 , and the last rifle actually made by a Hawken was built in 1884 . Although popular with mountain men and hunters of the fur trade era , up through the mid part of the 19th century , muzzleloader s were generally replaced by mass - produced , breech - loading weapon s such as the Sharps rifle and the Winchester rifle . Design . The rifles are generally shorter and of a larger caliber than earlier “ Kentucky rifles ” from which they descend . The style of the rifles is the same as the Harpers Ferry Model 1803 , a half stock rifle ( although they also made some with full stock ) , with the same lines as the Kentucky Rifle . The " plains rifle " style would become the " sporter " for much of the United States during the 1840s . Their " Rocky Mountain " guns were typically . 50 caliber or . 53 caliber , but ranged as high as . 68 caliber . They averaged 10 and 1 / 2 pounds , although there are examples of 15 pound guns . Barrels were of varying lengths ( 33 and 36 inch examples are described ) , and are octagonal on the outside and made of soft iron , which reduced fouling . The walnut or maple stocks have a curved cheek piece , often looking like a beaver ' s tail and called that . They tend to have double triggers ; the rear trigger is a " set " trigger . When the rear trigger is pulled , the hammer does not fall but rather the action " sets " the front trigger , the front trigger becoming a " hair trigger , " tripped with a light touch . When the front trigger is used without using the rear " set " trigger , it requires a firm pull . The front site was a blade sight . Unlike many modern reproductions , the butt plate and other trim was not made of bronze , but of iron . The 1972 film " Jeremiah Johnson " starring Robert Redford as a mountain man who used such a rifle , and contributed to general interest in replicas and a resurgence in the popularity of muzzleloaders among modern hunters .