Unless you handload, a 7mm-08 will most likely only have a 140 gr bullet max. And .308 will usually start at 150 and go up to 180 or more.
I guess I should have added handloading. I can push a 140grXLC, to within 3,000fps and have no pressure signs, and my gun has a 20" barrel
Winchester load using the Ballistic Silvertip:
7mm-08 with 140 gr: Muzzle velocity 2770 Muzzle energy 2386 400 yards- MV 2026 ME 127
Wow, I never realized that the factory loads were so whimpy.
But with the .308, you can get factory ammo with 180 gr bullets of stout construction that are better for big boned critters like elk.
With the premium bullets around today, especially the barnes bullets, thats really not a concern anymore.