A method of manufacturing one of a range of autoinjectors (100, 100', 100") having cartridges (600, 600', 600", 600'") with different preset fill volumes, the method comprising the steps of: a) providing a front body assembly (100b, 100c, 100c', 100c"), b) providing a cartridge (600, 600', 600", 600'") of given fill volume, the cartridge comprising a cartridge body extending along an axis and a piston axially slideably arranged within the cartridge body, the cartridge body defining a distal outlet portion and a proximal open end, c) providing a rear body assembly comprising a rear body housing, a drive ram assembly (310, 320), and an actuator for providing a force arranged to act on the drive ram assembly (310, 320) to drive the piston of a held cartridge (600, 600', 600", 600'") distally, whereby the drive ram assembly (310, 320) is releasably held relative to the rear body housing against the force of the actuator, d) providing a ram spacer member (400, 400', 400", 400'"), the ram spacer member defining a spacing geometry of length dimension (X1', X1", X1"', XS', XS", XS'", XR', XR", XR'") selected from a range of ram spacer members (400, 400', 400", 400'") having spacing geometries of different length dimensions (X1', X1", X1"', XS', XS", XS'", XR', XR", XR'") according to the fill volume of the cartridge (600, 600', 600"), and providing, on the ram spacer member (400, 400', 400"), a first sound generating geometry configuration (403, 403', 403") that for the assembled autoinjector (100, 100', 100") is configured for cooperating with a second sound generating geometry configuration associated with the housing (200, 220) of the autoinjector (100, 100', 100") to generate one or more click sounds during an expelling operation, wherein the method step d) includes the selection of a ram spacer member (400, 400', 400", 400'") from the range of ram spacer members (400, 400', 400", 400'") having differing click sound generation geometries, and e) assembling the front body assembly (100b, 100c, 100c', 100c"), the cartridge (600, 600', 600"), the ram spacer member (400, 400', 400") and the rear body assembly so that the ram spacer member (400, 400', 400") is axially arranged between the drive ram assembly (310, 320) of the rear body assembly and the piston of a held cartridge (600, 600', 600"). a) providing a front body assembly (100b, 100c, 100c', 100c"), b) providing a cartridge (600, 600', 600", 600'") of given fill volume, the cartridge comprising a cartridge body extending along an axis and a piston axially slideably arranged within the cartridge body, the cartridge body defining a distal outlet portion and a proximal open end, c) providing a rear body assembly comprising a rear body housing, a drive ram assembly (310, 320), and an actuator for providing a force arranged to act on the drive ram assembly (310, 320) to drive the piston of a held cartridge (600, 600', 600", 600'") distally, whereby the drive ram assembly (310, 320) is releasably held relative to the rear body housing against the force of the actuator, d) providing a ram spacer member (400, 400', 400", 400'"), the ram spacer member defining a spacing geometry of length dimension (X1', X1", X1"', XS', XS", XS'", XR', XR", XR'") selected from a range of ram spacer members (400, 400', 400", 400'") having spacing geometries of different length dimensions (X1', X1", X1"', XS', XS", XS'", XR', XR", XR'") according to the fill volume of the cartridge (600, 600', 600"), and providing, on the ram spacer member (400, 400', 400"), a first sound generating geometry configuration (403, 403', 403") that for the assembled autoinjector (100, 100', 100") is configured for cooperating with a second sound generating geometry configuration associated with the housing (200, 220) of the autoinjector (100, 100', 100") to generate one or more click sounds during an expelling operation, wherein the method step d) includes the selection of a ram spacer member (400, 400', 400", 400'") from the range of ram spacer members (400, 400', 400", 400'") having differing click sound generation geometries, and e) assembling the front body assembly (100b, 100c, 100c', 100c"), the cartridge (600, 600', 600"), the ram spacer member (400, 400', 400") and the rear body assembly so that the ram spacer member (400, 400', 400") is axially arranged between the drive ram assembly (310, 320) of the rear body assembly and the piston of a held cartridge (600, 600', 600").