The only load that regulates for me in a Westley Richards is, for lack of a better term, the Siefried load of 89-90 gr of R15 under 6.5 gr of dacron with the Woodleigh soft for 2130 f/s.
Reduce by 2 gr for the solid for the same velocity.

One thing to keep in mind is quite a difference in case thickness. Federals weigh about 320 gr while Bertrams are at 350. Best not to mix them up.

Pete

There is nothing made by man,
which cannot be broken by woman.