The present invention relates to a bullet-projectile and case feeding device, characterized in that it comprises a drum (1) internally provided with at least two compartments: a concentric inner compartment (6), and another outer compartment (7), wherein the compartments (6, 7) are suitable for housing cases or bullets-projectiles. The bottom of the drum (1) has an inclination of essentially 45° to 70°, the compartments are provided with: first housings (8) and second housings (9) forming positioning means for positioning the bullets-projectiles and cases, and one inner tube (3) and one outer tube (4) per compartment for feeding the assembly press, said bullets-projectiles and cases being moved in a disorderly manner when the drum rotates (1) and accessing said inner tube (3) and outer tube (4). The device is used in a feeding method for feeding bullets and cases to an assembly press and in a case annealing method.