15×103L
15x103L refers to a specific type of firearm cartridge. The designation "15" indicates the approximate bore diameter of the projectile in millimeters, though the actual diameter may vary slightly. The "103L" denotes the length of the cartridge case in millimeters, with the "L" often signifying a longer or specialized version of a base cartridge. This particular cartridge is not a widely recognized or commercially produced military or sporting round.
Information regarding the exact specifications, ballistic performance, and intended use of the 15x103L cartridge is scarce