The M59 Ball bullet is GM with a steel core and a lead-antimony point filler, 1.28 inches long. Bullet weight is 150.5gr. Complete cartridge weighs 388gr.
The M80 Ball is either GM or GMCS with only a lead-antimony core and is 1.14 inches long. Bullet weight is 149 gr. Complete cartridge weighs 388gr.
My question is how can you differentiate the two without pulling the bullet? Was there an overlap in dates of manufacture or can this be used to seperate them. If they do not overlap in date, what are the date ranges of each type.