Gunsbam45 .... lots of good advice from the other members posting.
Just to add another option is to get on JBM or Berger websites and they have twist calculators. Input bullet, anticipated velocity, twist, bullet length, temp, elevation, etc and they ll give you a stable or not stable output to help give you a starting point.
As pointed out by one of the guys though, sometimes you just got to try it. Barrel twist rates aren't necessarily perfect/exact. Might say 9 twist and actually measuring it might give you a 1-8.75 rate... or, a 1-9.125 rate!!
Good luck