<P> The Browning Auto - 5 was the first mass - produced semi-automatic shotgun . Designed by John Browning in 1898 and patented in 1900 , it was produced continually for almost 100 years by several makers with production ending in 1998 . It features a distinctive high rear end , earning it the nickname `` Humpback '' . The top of the action goes straight back on a level with the barrel before cutting down sharply towards the buttstock . This distinctive feature makes it easy to identify A-5s from a distance . A-5s were produced in a variety of gauges , with 12 and 20 predominating ; 16 gauge ( not produced between 1976 and 1987 ) models were also available . The gun saw military service worldwide between World War I and the Vietnam War . A Remington Model 11 was used in the suicide of Kurt Cobain . </P>
when was the first semi automatic shotgun made
Designed by John Browning in 1898 and patented in 1900