I HAVE one...
Sorry, but i must disagree, there is a such thing as a 30-08 i have seen one and fired one.
I don't know everything there is to know about guns, but I know enough to have confidence in saying this:
Whoever told you that gun you were shooting was a "30 ought 8" didn't know what the h*ll he was talking about.
Until you can provide some proof of this ridiculous claim of yours, I'm calling "bullsh*t!"
I actually have a Peruvian Mauser (GEW 98 export) originally chambered in 7.65 x 53, and still marked as such. However, the first time I fired it, I blew the necks out of four rounds. I found the chamber fit a 30-06 round perfectly, but the bore slugs at .312, which is normal for the 7.65. It WILL fire the 30-06, but accuracy is much better with a .312 bullet that I cast for my Enfield (180g gas check, 21 Brinnell). (The reason I quote you is that 8mm is .314, so this COULD be considered as a 30-08 or 08-06, or whatever you want to call it.). I load 30-06 range brass with the .312 bullets without neck sizing, using a 30-06 powder thru expander die. I then collet crimp the neck with a 303 British crimp die. (Probably unnecessary as the bullet fits nicely in the unsized neck). Trim length is standard 30-06. I CAN shoot factory 30-06 ammo, but the possibility of gas leakage around the smaller bullet makes me avoid it.
The rifle was too nice to dump, ( someone did ivory inlays and stock carving in the past) so this was my solution to shoot it. I understand dies for this combination are actually available, but being a cheap SOB, I used what I had. The step from a .309 30-06 bullet diameter to .312 isn't much, so it wasn't hard to do- The neck expands that much when the round is fired.
It was a labor of love, and it shoots really sweet, tight groups.