Corvus,
You did nothing wrong. It's easy to fix. Your wish is my command. Moved to the Ballistics section.
Bernd
Thanks Boss or should I say Genie

Having chambered quite a few barrels over the years so I can vouch for the info. The floating reamer holder is an excellent idea. I have a commercial version, but the one he describes is more than adequate and a lot more cost efficient.
I have previously made some chamber reamers but they were the half reamer type, where the profile is cut in half and then sharpened, these work well but I always wanted to make a fluted reamer.
For a while now I have had a project idea for a .45-70 and as soon as I find a decent barrel blank I may look at making the reamer like this.