Before reloading, some hulls may require a little reshaping of the hull mouth. Some hulls have a very strong "memory" and will maintain only a partly opened crimp after being fired. Sometimes, hulls will be creased in the press during the crimping process. Sometimes you just need a fresh crimping surface. The Spin Doctor's special shape, when combined with heat generated by friction, gently recondition damaged hulls. The tool reshapes the crimp mouth by rolling back the shruken plastic mouth and smoothing the rippled plastic. Fits in any standard hand drill or drill press. The Spin Doctor saves expensive hulls and returns factory-sharp crimps.