I'm using 56-50 blanks by Veteran's Arms, and since I use them in my 56-56 quite well, that in itself probably is ruled out.
It is a Cimarron Arms, the original owner took it back to the company (he lives close to them) and had them convert it to 56-50. The barrel has a different serial number, and he told me they switched the barrel from the 45 to the 56-60. What I don't know, and I don't think he does either, if CA changed anything else, or if they had to and might not have. I think I will call them tomorrow and see if they have, and will divulge what the history of the piece might be.
I am unimpressed with how thin the magazine tube is. Thin to the point of being sharp, and easily dinged. To bevel the opening, I used the shaft of a screwdriver and just ran it around the opening.
Right now, I'm only going to use blanks for reenacting, not really wanting to put a live round in something I'm not sure of. I still have all my fingers and nose and I kinda like it.
I have slowly racked it, but tomorrow I'll do it and see if I can analyze what is going on better.
I don't think racking one hard is correct and acceptable, that goes against reasonable treatment of a fine piece of machinery.