SL1, the 47.8 grain charge in the .308 (the one that showed gas leaking around the primer) "just filled the case" when I seated to about 2.815. So the one I am going with has the case just a touch below full.
I am a little concerned about throat erosion and "burning up the barrel" in general (is that just throat erosion?) but I figure the ultra-high-end loads won't be as accurate as the loads that are more like book max or a little below. So I won't be firing enough cartridges at those high levels to do any damage...I will work down past them quickly enough. I plan on firing 25 cartridges per load level as I am not a good enough shot for 1 or 2 groups at a given load level to mean anything.