The M7 is the U.S. Army’s newly type‑classified service rifle (the Army designation for SIG Sauer’s MCX‑SPEAR), built for the Next Generation Squad Weapon (NGSW) program. It fires a new 6.8×51mm “common” cartridge (often called .277 Fury) rather than the 5.56×45mm used by the M4/M4A1; that change gives greater range, energy, and improved ability to penetrate modern body armor. The M7 also comes with updated magazines, a different operating system and is paired with new fire‑control optics as part of a broader squad‑weapons package.