The invention relates to manufacture of a cup (1) that is designed to serve as a blank in the production of a metal shell (2) by providing a body (3) of a bar material, placing the body (3) in a counterdie (6) in which a first end surface of the body (3), which is substantially perpendicular to the central axis (C) of the body, is placed facing towards the bottom of the counterdie while the inner wall of the counterdie (6) encloses at least a part of the body and preferably the whole body, so that the body (3) is hereby placed in the counterdie (6), applying a mandrel (9) to a second end surface of the body that is substantially perpendicular to the central axis C of the body (3), applying a pressing force to the mandrel (9) so that the body (3) is cold flow pressed through plastic deformation into a cup (1). The invention also relates to an application of a body for manufacture of a blank for a grenade/cartridge shell and a process for manufacture of a grenade/cartridge shell.