 The XP-100 action was used as the basis for a new single-shot rifle from Remington called the XR-100 Rangemaster.While the XP-100 has disappeared from Remington's lineup (Remington is primarily a maker of rifles and shotguns), the .221 Fireball remains in production.The Model 700 rifle has been available since 2002 in a .221 Fireball chambering; while it lacks the velocity attainable with the vastly more popular .223 Remington, the short .221 Fireball delivers most of the performance with far less noise and flash.