I recently came across a cartridge compatibility chart I received from somewhere a number of years ago. I browsed over it and found nothing particularly earth shattering until I came to one section which caught my eye. It stated that the .303 British and the 7.7mm Arisaka cartridges are completely interchangeable. I knew the bullet diameters were identical between them, but I would never have thought they were interchangeable. Can anyone confirm or deny this? Would it be safe to actually fire .303 British ammo in a 7.7mm Jap rifle?