10 twist can shoot a number of bullets from 155 to 208/210 just fine in a .308. All comes down to needs. In my .308s I like a mid range bullet. I don’t like really heavy as they can cause oal issues and need single loading and run slow or the lighter bullets as the BCs are usually lower.

I like a 168-178 range bullet for my .308s especially now with the better bullets available. You get a good BC and can get good velocities. The 175 SMK you are using is a decent bullet but has been left behind in the weight/BC department. They can still work and I used them in the past to shoot over 1000 but better options now. I run a 168 ELD-M now in my match rifles. Have shot them to 1250 yards in matches. I get a higher BC and get velocities around 2800fps which is max for my sport. The BC is .526 versus the 175 SMK .496. Also others out there like the 178 ELD-M, 169 TMK and the Berger offerings. Just some others to think about and maybe try.

So don’t stress too much about optimal for the twist but optimal for the use. The 10 twist will stabilize them all.