A system for reloading a cartridge including seating a primer in the cartridge for use in a predetermined firing chamber includes at least one reloading die and reloading shim adapted to selectively insert into the chamber. A desired seating depth is determined and an offset factor is determined using a primer pocket depth, a primer height, and the seating depth. This calculated dimension is transferred to a primer-seating press. The primer-seating press includes an arm hingeably configured to operate in a first position, a second position, and a third position; a cross pin configures on the press horizontally and selectively slides from a retracted position to an extended position and an adjustable stop disposed on the arm. The stop is pre-set to using the calculated dimension to limit travel of the arm by cooperating with the cross pin. The seating press includes a vertically arranged piston operated by the arm.