H4895 or something better?

I lean heavily toward Hodgdon powders. For me they are very predictable and consistent.

There are lots of powders that can be used for both calibers. I've never tried H100V, it is not listed for 308.

If you prefer to use the same powder for both calibers, H4985 or Varget are fine choices with good history of consistency and accuracy. It seems like Hodgdon likes the slower powders for the 25-06. If you are willing to use different powders H4895 for 308 and H1000 for 25-06.

Load em', shoot em', smile.