Your response was not rude Pettifogger. You are correct in that I don't have much experience with 1873 type rifles, in fact this is the first one I have owned and shot. I apologize if my definition of head space was confusing or not correct, but I have always referred to head space as the actual gap between the cartridge head and the bolt face and most people have understood my meaning. There are too many variables if one includes rim thickness when describling head space as different cases can have different rim thickness. Just for the record, I have been around firearms all my life and in my career, so I am not ignorant when speaking about them.
If I sound frustrated I am. I ordered this rifle FROM a gunsmith who, at my request, installed a short stroke kit in it. It took almost a year for me to get the rifle and when it came I was like a kid a Christmas. Unfortunately, my very first shot with the rifle was a .357 magnum that ended up cracking the case resulting in a case head separation and breaking the tab off bolt number 1. Since that time I have sent the gun back to the gunsmith several times and for whatever reason the fix eludes him and me. So right now I have almost $2100.00 in a $1200.00 gun. The gun should be eligible for frequent flyer miles because it has been shipped so often.
I have spoken to several gunsmiths about these rifles and have received more than one version of how these rifles head space and operate. I am familiar with the timing issue you mentioned, but I don't believe that is the problem here. I posted this thread in the hope that perhaps someone else has experienced the same problem as I have and perhaps could offer another suggestion or cure. So rather than risk sounding stupid or irritating you or anyone else I will refrain from saying anything else. I appreciate the help you offered, but I have sent the rifle to a well known gunsmith more than once, actually at least three times now and it still ain't right. Thanks, Rick