Well there are 2 loads with 100 grain bullets and one with 95 grainers using URP listed.
URP is I believe, very similar to Reloder 19 if that helps widen your search perimeters.
Try it, if you only have a small amount, what do you have to lose?
The classic Norma powder for 243w and heavy bullets would be MRP, with 204 a close second?
Viht wise, N160 and N560 probably go to powders.
Plenty of data out there for 243w/100grain bullets.....