Several reasons not to go to fast on twist. One of the easy ones, I have experienced is the greater RPM's of the bullet. Too fast and they will sling apart[350,000 rpm or so]. Seems to be a good bit of info on what works best in a given caliber and a given cartridge. What were you looking for in particular.
Well I'm looking at pushing a .366 cal 250gr bullet at 3200-3500fps; a 286gr around 3000-3150fps and a 300gr about 2900-3100 fps. I know that the standard twist for this caliber is 1-12 or 1-14 but was thinking of going with a 1-10. Not quite sure why, just feel that the faster twist and a 26" barrel would be better suited.