Good rule of thumb, tighter the twist, heavier the bullet...basically, the lighter the bullet, the slower it's going, so to get the same RPM's it would need a tighter twist rate.

On your .308, 1:10" is pretty tight, but it's not overly so, your rifle should shoot very well with 175grns and 180s, but there's no reason it won't shoot very well with 150's or 130's even. I've got a 1:10" that I run 100 and 110grn (.30-06) bullets through, at max velocities they shatter at leaving the muzzle, slowed down a bit I get about .5MOA accuracy to 200yrds, 300 on a calm windless day (which happens about once every other leap year in KS), it also shoots 180 and 200grn bullets VERY well, the velocities are much lower than I can push those 100's to, but like I said, I must limit their speed.