...then I took them out of the handles and found the locator pins were loose in the holes.
Not the pins themselves, the holes in the other half of the blocks.
Based on the mic, the blocks were sitting twisted from each other for a total offset of about .005.
So I thought about hammering the locator pins deeper into the blocks a bit (hole is open to the backside) to see if they would center again, but they won't budge with the blows I'm willing to commit to.
Then I noticed that the steel I was going to put under the mould blocks and the steel I was going to put on top to meet the hammer head was NOT that flat. Good thing. The thing's going off to RCBS in the next mail run. They have the hydraulic press (I assume) that put the pins in in the first place anyway.
If not for this, I'd be knocking out 500+ tonight. Bleh. Moulds have NOT been used that much either.