I wouldn't think that .001 is enough of a difference to cause the hangup that's been described. Primer cups are soft, and the anvil underneath is not all that firm either. Just the ram pressure from your seating tool, meeting hard resistance, could likely flex the primer at least that much I would expect. I've never tried Wolf primers--I usually stick to Winchester--and CCI if I cannot get Winchester. Even at that, it feels like some seat a little harder than others. I agree with those who've suggested cleaning out primer pockets as part of the process. It's a step that even I've been ignoring at times. From what's been said, here, though, I don't think that the height of the primer is the problem. I'd like to read more about this from you guys with experience with Wolf primers. I've been thinking of ordering some in large rifle, small and large pistol, and shotgun.