I noticed that when I am trying to use my honady comparator on some brands of brass I am geting over .001 of variance when I spin the cases in the calipers and the comparator, and all of the chatter is coming from the case head on the caliper jaws. Did some looking into this and found that the deep stamping on the case head by some mfrs is causing peaks and valleys, and in one case I found the entire head was coned slightly, I suppose becuase the stamping was covering the case head. When I took a couple of the cases that had this issue and ran them across a FINE whetsone (head flat against the stone), this variation went away and was able to get consistent readings. Not a lot of removal - just enough to get rid of the high areas and produce a flat surface to measure off of. Seems to work well, though not techinically "trued". The reason this is important to me is that if I am using a comparator to set my bullet jump or a slight crush fit/touch to within .001, the friggin' case head may cause me to be off, which throws off the data that I think I am using. So, is anyone truing up case heads? If so, how are you doing it? Oh, and, once again, Lapua doesn't seem to suffer from this issue as much as others, and I noticed that their headstamps are much shallower than the rest.