The United States Army currently uses the M4 Carbine as its standard-issue service rifle. The M4 is a shorter and lighter variant of the M16 rifle and fires 5.56×45mm NATO ammunition. It features a telescoping stock, 14.5-inch barrel, and a gas-operated, direct impingement system.
The Army is in the process of adopting the XM7 rifle (formerly called the XM5) as part of its Next Generation Squad Weapon program to eventually replace the M4. The XM7, manufactured by Sig Sauer, fires the new 6.8×51mm cartridge and was selected in April 2022, with adoption gradually beginning in 2023-2024.
Some specialized units within the Army may use different rifles for specific missions, including variants of the M14, M110 Semi-Automatic Sniper System, M24 Sniper Weapon System, and others tailored to particular roles and requirements.