If your worried about not enough expansion of a 308 Winchester or 7mm/08,,, then why not buy factory ammo that does expand...
There are 7 + manufactors that produce 50+++ types of bullets that will expand on thin or thick skin critters of your choosing...
Find the bullet your after and get at it,,, lifes to sort to find the best of the best...
Do your research on the factory ammo bullets that are available and get at it...
If you don't like what is out there, start reloading your own ammo...
I switched to Partions for my 30/06,,, 308,,, and 6.5 since they work...
Cheers from the North