Based upon the terrific feedback you all provided in Part I, I cleaned the rifle thoroughly to include the muzzle. I grabbed a pile of factory ammo and my reloads and headed off for the range. I started at 100 yards and fired 10 factory and 10 reloads in separate targets - while the grouping pattern was different between them (my reloads were tighter and more consistent) there was NO keyholes. Happy with what I saw I headed off to the 200 yard range and did the same thing. The groups were tight (for me) with both factory and non and there was still NO tumbling. The only thing that I think made a difference was cleaning the muzzle. There was definitely carbon build up but nothing I would have thought to cause the tumbling. I fired around 100 rounds and each paper impact was a nice 22 cal indent in the shoot n c target. life is wonderful again. thanks for all of your help and guidance. Keep your rifles clean and clean your muzzles!!