The present invention relates to a process for manufacturing a projectile made of steel or based on iron, for a hunting or sports cartridge, for the purpose of giving it a Vickers hardness at room temperature of between 40 HV 10 and 110 HV 10, preferably between 40 HV 10 and 85 HV 10, characterized at least by the following successive steps:--liquid pig iron or steel is used, hereafter called liquid metal, the carbon content of which is between 0.8 and 4.0% C by weight, preferably between 0.8 and 2.0% C by weight;--the liquid metal is cast using a steam or water-vapour granulation process to obtain spheroidal steel particles;--said particles are subjected to a heat treatment for softening the solidified metal by graphitization, while remaining in the ferritic range; and--optionally, said particles are subjected to a surface coating treatment.