I have an old "Pacific" reloading manual. This manual states that the 8x57 Mauser in a 98 acion will match the .30/06 in vel. with the same bullet weight due to it's greater expansion ratio making up for the lesser capacity case. Both ctgs. of course, loaded to the same pressure level.
The 8mm/06 of course, handily beat the '06 due to it's greater expansion ratio and same useable case capacity.
The 8x60 should be in the same ball park as the 8x57 Mauser.
I've read the .30/06, with it's normal rate of twist of 10", did not stabilize it's. 308" 250gr. bullet well even though it was capable of driving it at 2,450 fps.