Originally Posted by MachV
I've loaded the 338/300 RUM down to 338RUM specks and still the primers are not staying in them? No other signs of preasure = just loose primer pockets.
Looking for visible signs of pressure is not a good thing to do. Some cartridge brass won't show any visible signs of high pressure even if it's proof loads.
Primer pockets being too loose to hold primers after a few reloads is a sure sign of too much pressure. If cases fired in a given barrel end up with loose primer pockets before they've been shot 20 times, I think they're loaded too hot for the load and barrel used.
'Course we all get to define our margin of safety depending on our desires.