I loaded up 40 rounds of 348 Win a month ago. I used a 200 gen Hornsdybballistic tip over some ancient 760BR. The books said 58 grains was a max so I used 56 grains. Unfortunately I used a mixed lot of brass, new Win, old Rem Pete and some old old once fired Winchester. At the range all was good unti I lit one of the Rem Peters rounds. The action got very hard to open. Two more Win rounds were OK then one more Rem round. This one opened the action. So, I知 going to pull it all down and back off 5 grains. As I see it, two factors are at work here. The 760BR is old and must have a hotter burning rate. And 2, the older Rem cases must have a much smaller capacity. I値l check that tomorrow. I was lucky