<Tr> <Th> Feed system </Th> <Td> 15 - round detachable box magazine </Td> </Tr> <Tr> <Th> Sights </Th> <Td> Iron sights </Td> </Tr> <P> The Beretta M9, officially the Pistol, Semiautomatic, 9mm, M9, is the designation for the Beretta 92 semi-automatic pistol by the United States Armed Forces as their service pistol . The M9 was adopted by the United States military in 1985 . </P> <P> The M9 won a competition in the 1980s to replace the M1911A1 as the primary sidearm of the U.S. military, beating many other contenders, and only narrowly defeating the SIG P226 for cost reasons . It officially entered service in 1990 . Some other models have been adopted to a lesser extent, namely the M11 pistol, and other models remain in use in certain niches . </P>

What is the official sidearm of the us army