Apprently you can change the caliber by simply swapping out the slide... Eh?

FNP9, very long hair, red-framed eyewear, pink hair, blue eyes, black headwear, pencil skirt, side slit, black skirt, white gloves, braid, hair flower, white shirt, black jacket, white thighhighs, garrison cap, garter straps, under-rim eyewear, short sleeves, open jacket, hair ornament, 

holding gun, handgun, 

high heels, black footwear,