Re: 22-243 win loads
I'm thinking you might look at .220 Jaybird data which is the spitting image of the .22-243 Middlested; another might be the .224 Clark
In some of the original pressure data RL21 and H4831 worked well in bullets from 60grs to 72grs..
You might also consider using data from the .220 Swift which 4gr to 5gr less case capacity than the .22-243
Other powders that may show promise are; N205 and IMR-4350 or there equals. Most of the information you'll find won't include bullets weight much heavier then 75grs... With today's powders and heavy bullets, a guy could work up a real barn burner I'm sure.