If you lump together all the .506 to .510 rim diameter cartridges there are a bunch. The .506-8 rim is the 45/70 or 45/90 case and the .510 the 348 case. There are a couple of metrics and the 280 Ross in this same rim diameter range.

So check out what has already been done or is available off the shelf before dropping the hammer on the project. A completely new wild cat will set you back at least $4-600 over an existing one with dies already available. I have never done it as I never get past the $$$ research point. I always settled for a more common chamber usually an AI but not a full blown wildcat.

"When you disarm the people, you commence to offend them and show that you distrust them either through cowardice or lack of confidence, and both of these opinions generate hatred." Niccolo Machiavelli