kombi - I like to equate different bullet weights and diameters for comparability. Some folk are going to shoot me in the butt for this but it has worked for me in the past and I hope it works for you.
The 8mm has a .323 bore, the 06 has a .308 bore. To me, a 170 gn 8mm, even at good reloaded speeds, would hit about the same as a 150 gn 06 - lots of meat damage on medium to large size deer. The 180-185 gn 8mm hits like the 165 gn 06s and probably better than the 165 gn 308s. Some of the Hornaday light magnum loads for the 06 carry the 165 gn load, I think, and that is a pretty good load. The 8s a 196-200 gn load is at least on par if not better than the 180 gn 06 load. A 200 gn 06 load at 2500'/sec will or should penetrate farther than an 200 gn 8mm load, but I think they are really pretty equitable on the business end.
I don't feel that a properly loaded 8mm gives up anything to a 308 or the 30-06. I would take either one for boar or bear, although for the later I would prefer my heavy 444. Just my thoughts and hth. Mikey.