just make it full size, which is 81.7 centimeters long (from the tip of the blades to the back of the handle) and make the scale MC's height (86 i think). so whenever someone makes it, they can just input their height for the scale and itll make it scaled to them.
i think itll work like that
cant wait to see that shotty done, ive been waiting for awhile for a good shotty.