Abstract: A shell reforming system and method is shown comprising an automatically temperature-controlled and detachable heat mandrel on which a shell may be situated for a predetermined period of time. The system and method further utilize a plurality of detachable cooling mandrels which facilitate cooling the shell and deforming it to a desired shape, such as a generally elongated cylinder shape. The system and method is suitable for handling multiple gauge shells and for maintaining and controlling the temperature delivered to the heat mandrel so that shotshells may be reformed consistently. A method for reconditioning and reshaping the shotshells using the automatically controlled heat source is also disclosed.