Don’t know if this helps but you’re welcome to try:
Optimum load for my RPA 1:10 twist 69g match kings
RS40 22.2 grains
COAL 2.253
I’m getting 5 shot groups of .4” @ 100 yards
I tested 10 different loads from 21.3 - 23.9 and the above formula really stood out from the rest.
All shot using a front bench rest and rear bag.
I did start off with 2.26 coal but reduced it slightly as the bolt wouldn’t close on a couple of round during initial testing so I figured it was getting a bit too close to the max length.
I’m new to reloading so happy with anything .5” or less at 100 yards.
They have performed well at 300 & 600 yards.
Best of luck