.480

.450 is the cartridge that was chambered for an interchangeable barrel for the SRS 99C - S2 AM Sniper Rifle that Linda used on her first mission to capture Colonel Robert Watts, which was a success.

Trivia

 * .480 means that this ammo type is twelve twenty-fifths of an inch wide.
 * This ammo size is about 12.192mm.
 * .480 is a real-life ammo type, used in revolvers.