10×24mm Caseless

The 10×24mm Caseless, designated the M309 in Salisfordian Military service, is an Salisfordian-made caseless rifle cartridge notable for being the primary ammunition used by the L5A2 and its variants

Overview
The cartridge consists of a 210 grain (13.6 gram), steel-jacketed and explosive-tipped projectile embedded within a rectangular propellant block of Nitramine 50. Although the propellant mass is small, it is highly efficient, generating muzzle velocities of 840 meters per second. The M309 is optimized for lethality against infantry wearing personal armor, with its factory pre-set impact fuse designed to explode after the round has penetrated armor to inflict maximum damage. Consequently, the round is less effective against unarmored opponents, as it will often over penetrate soft targets without detonating, leaving the victim relatively unscathed and necessitating the use of multiple hits to score a kill.