A method for chopping a body consisting of explosives is described, by which a high-pressure water jet emerging from a nozzle is directed against the body of solid explosive and in which the nozzle and the body carry out a movement relative to each other during the chopping. Preferred fields of use are composite rocket fuels. There is also described a device for carrying out the process, in which the body of composite rocket fuel to be decomposed or divided into portions is secured on a chopping bench, and a nozzle fastened to a nozzle holder for the high-pressure water jet as well as at least one means for producing a relative movement serving as chopping advance movement between the nozzle and the body of composite rocket fuel are provided.