I suppose your right. The more I think about it, the more I believe that perhaps the 1st firing of these rounds caused the case to expand a little and with me sizing them, it's squeezing the case down a bit.
As long as this is for my wheel gun, I doubt that it will make a difference. I loaded up a batch for a friend of mine to use in his Henry 45 rifle. So far he has not told me that he encountered and problems. I know that he used some in his Judge revolver and they were O.K.
Thanks for the reply.