Be careful with german aircraft armament. You need to know if the gun used a mechanical firing pin or an electrical connection to set off the primer. The MG17 was mechanical and needed a synchronization device for firing between the prop blades. The MG131 ammo was electrically primed, so used a timing device something like the distributor concept from older cars. Electrically fired primers allowed a higher rate of fire through the prop blades. In the case of the MG131 replacing the MG17, it allowed an almost similar rate of fire with a heavier round.
