I was given a box of late 60's .308/7.62 brass and two things were apparent. It had been shot through an M-60 and was tougher than my High School Algebra Tests.
When full length sizing It felt like I needed an extra 2 feet on the handle of my Rock Chucker in order to get the case all the way into the die with really good lube.
Once initially processed it lasted what seemed like forever. Capacity seemed to be less than later stuff but I never really measured it carefully.