Bret4207
At the casting bench in the sky. RIP Bret.
Using a proper old school micrometer and gauge set, and not my harbor freight digital calipers.
Just measured the ID of 10 federal non- typical 180 grain shot in my 30-06 they measured from .3093 to .3098
The rifle is a savage axis BTW. So I am guessing a .310 to. 314 bullet??
At least .310. This is the next step where you have to try and see what will chamber and how fat you can go. You're going to have to watch what happens during seating. You don't want to "squish" the bullet in seating. You might end up having to use some form of "M" type die to expand the neck a bit, but at least you have an idea of where you can start.
I've said for some time that a fired case indicates how fat a bullet you can easily use, but that's wrong. I've fumbled the wording on what I was thinking. It's an indication of where you can start. Go no smaller than that for sure. I failed to factor in brass spring back and crimp and some other stuff- my bad. I think I have the right idea to pass on to a noobie, I just didn't carry the explanation out to the end.