When I was just shooting the Uberti, I automatically thought there was a problem with my brand new revolver. But when I experienced the same problem even down to the statistical likelihood of the misfire in the Vaquero, I figured there was little chance that two brand new pistols had the same problem.
The Auto-Primer will force the primers futher into the case than the press does. You can tell the difference by running your finger over the case. I also tested this by auto-priming fifty rounds and only using the bench press on the rest of the cartridges. No change whatever.
Just like you, if I cycle the round for a second shot, it frequently goes off.
Out of 250 rounds last Sunday, I brought home three that would not fire even after trying three and four times. Pulled them apart with the collet and recycled the brass. I should have carefully marked the ones which do not work on the first try.
The "Revolver Armoror" guy (don't know his name) has a very good reputation in this area and a very successful business. He seemed quite certain I had a bad batch of primers.
I will let y'll know how it goes.
My reading of history convinces me that most bad government results from too much government. Thomas Jefferson