H4350 is a winner so is RL19. I can't give you a recipe as I shoot a .260ai.
Hogdon shows 46.5gr as max.
Alliant shows 46gr for a 129gr Hrdy.
Use those as max., drop 3gr & work up.
I am doing real good with R19 in my 260s with both 120gr BTs and Sierra MKs. I prefer a little more bullet for hunting, but that need is debatable. I have also had pretty good luck with H4831sc and this bullet wgt. The accuracy was good but the velocity was a little lower in my rifle. You might want to try it though if R19 doesn`t please you in yours.