Im a bit confused about the .466 bore with a .468 groove.
Thats only .001 of rifling depth.
Brents point about whether you want to shoot black or smokeless will get you on the right track so think of that first.
If you want to use black powder, I would suggest using a pin gauge to measure the bore. That is the easiest and most accurate way to do it.
By doing that, you know the exact size of the bullet that will chamber and the groove depth is of no consequence.
If you really do have a .466 bore, that means you can patch virtually any .458 bullet right up to that .466 with two wraps - rather convenient!
What did the case neck/mouth measure at?
