Making a rimmed version of the 6.5 TCU from 5.6x50R. 1st trick is finding the parent brass! :)
Anneal, FLS in a Hornady die (decapping/expanding stem removed), trim to 46mm, fire-form in a chamber insert made for 410 scatter gun (hey! I had a special chamber reamer made for this "non-standard caliber: may as well get some use out of it!), neck ream the case while seated in the sizing die (had my gun doctor make a reaming tool to fit the Hornady die: works like a champ!), Fire-form again. Load, go punch paper.
Is TRULY a labor of love, and I am pleased I have 200rnds completed, so as I NEVER have to do THAT, again! :)