I use H414,IMR4350,IMR4895,IMR3031 and H4831SC. All work extremely well in a 243. My brotherinlaw swears by VARGET,but I 've never tried it yet.
Greyghost,
Some of the bullets over 100gr reguire a different twist than "normal" bullets. I tried some of the heavier bullets in my Interarms Mark X. When I finally got them to group decently, I was using 3gr over maximum listed for the powder and was using a Mag primer. I did approach this cautiously,so please don't blow me out of the water for admitting it.
HWD