Just finished a build with the following. Krieger heavy palma barrel with 1:12 twist and 30" finished length. The bore is .298 Has anyone hand loaded 155 - 168 - 175 SMK HPBT in .308 for this setup ? Looking for a starting point with Varget.
I've got a Bartlein tight bore barrel and I just started load development all over at the beginning. It was no different than starting for my factory barrel.
It's kinda hard to give you a starting point for a twenty-grain spread of different manufacturer's bullets without even a description of the chamber, brass, or primer being used.
Maybe first consult the .308 load section on this site, then narrow down your question.
Sometimes people forget that this site is not only a waste of time, but also a resource.