Today I tried a few loads out, using privi brass, and n550 powder. I tried 2 different bullets, Nosler BT's and swift Sciroccos, both in 150gn. Both were seated 10thou off the lands which gave slightly different COL due to the different shape of the bullets.
The Noslers shot really well, no pressure signs right up to max load.
The sciroccos showed slight pressure signs (extractor marks) at a lower charge, and continued to show pressure signs as charge increased, groups were good.
One case blew a primer with a medium load and one primer leaked on tha max load. In terms of cases being tight the max loads were no worse than the lower charges, same for extractor marks.
So my first question is: why would 2 bullets of the same weight and same jump show different pressures?
And my second question is has anyone had problems with once fired privy brass, particulaly loose primers?
I should point out that most of the brass was unfired and had original primers as I had just pulled the bullets. only a couple had been fired once before, one of which blew the primer out, the primer that leaked was an unfired original.
I obviously won't be using this load again even though it shot quite well, can anyone explain the differences?