As someone who built a fast twist 25-06 several years ago I can’t recommend it unless you have nostalgia for the cartridge. It’s a fine cartridge but factory offerings are anemic to say the least and doesn’t compete with newer short action chamberings with significantly longer barrel life and efficiency. If you handload the 25-06 can be a screamer but you’ll spend a lot of time trimming cases. My 1:8 twist shoots 121 grain hammer hunters at over 3200 fps out of a 26 inch tube. These bullets have a pretty low real world bc but are very effective 450 and in.
A 6.5 prc can beat that velocity substantially with about the same powder with better BC. Factory 6.5 creedmoor matches factory 25-06 velocities at the same grain weight. A 6 creed is what I’d go for were I in your shoes with with information you’ve given. It’s a more efficient and modern .243. I say that as someone who owns a couple .243’s.
A 6.5 prc can beat that velocity substantially with about the same powder with better BC. Factory 6.5 creedmoor matches factory 25-06 velocities at the same grain weight. A 6 creed is what I’d go for were I in your shoes with with information you’ve given. It’s a more efficient and modern .243. I say that as someone who owns a couple .243’s.