Thanks to all who posted. You gave me enough ideas and moral support to pursue the issue to the end.
It seems the over rotation was due to an accumulation of issues. None of the problems would have caused over rotation by itself, although one issue would have eventually destroyed the gun. Here's what I've concluded:
1. There were significant machining grooves on the lead that carries the bolt down into the mortise on the cylinders of the guns. These grooves run axially to the rotation of the cylinder. They present mini-speed bumps to the bolt as it travels down into the mortise. These are evident when looking at the bolt notches with a jeweler's loop.
2. The top surface of a Rooooger bolt is cut perpendicular to the side surfaces. In other words, the bolt is 'flat' on top. Colt's bolts (good name for an after dinner desert) on the other hand are cut at an angle that matches the 'ramp' that leads into the cylinder mortise. So, on a Colt's bolt, the bolt is presenting a high point to the face of the mortise that stops the cylinder rotation. This configuration, as it exists on Colt's guns, makes for a much more positive index. It also presents more bolt material to the face of the mortise, which can lessen peening from stopping fast cylinder rotation.
3. The mortises on the offending Roooger were, in fact, peened to the point where there was a raised burr above the mortise on the 'stop side' of the mortise. It was clear on the problem gun that the bolt and cylinder were destined for failure at some point. This, I feel is a problem with the original fitting of the gun and does not speak well of Roooger quality.
4. As a number of you pointed out, grease has no place in the guts of a single action pistol. Oil will work just fine, thank you. Further, grease gets pretty sticky on cold mornings and has detergent in it wihich eventually turns the whole mass to sludge.
So, the wrong lubricant, on a cold day, on a pistol with a poorly fitted bolt, which ran in very rough lead-in ramps caused the bolt on my Rooger to skip over certain chambers at the State Match on the first stage, thus ruining my thousand dollar weekend.
Remedy:
1. Polished 'speed bumps' out of mortise leads to eliminate places where bolt bounced.
2. Reshaped the bolt to angle the top surface resulting in more positive cylinder locking. Also resulted in increased surface area on that part of bolt that stops cylinder.
3. Filed raised burrs flush and will monitor this location in the future for problems.
4. Used light machine oil in reassembly and only apply grease on ratchet, base pin, and cylinder extension (to help seal base pin from black powder fouling).
Once again, I've learned a complicated, difficult lesson about CAS gunz. I once asked a pard how long it had taken him to sort out his gunz for playing this game. He said, "ten years." I think he was right.
Thanks again for all your ideas and encouragement. Time will tell if my Roooogers are now more dependable. I suspect they will be. But, just to be safe, I ordered a pair of USFA gunz from Jim Finch.