Ten Bullets The new XM5 rifle and XM250 automatic rifles, which will eventually replace the M4 carbine and the M249 Squad Automatic Weapon respectively, will use the 6.8mm common cartridge family of ammunition. The Army announced April 20, 2022, that Sig Sauer, a firearms company, was awarded the recent contract to provide the new weaponry. SHARE: Download: Full Size (0.4 MB) Credit: Sig Saur, Courtesy Photo VIRIN: 220420-O-D0439-003M.JPG Photo Gallery