Relative to Cowboy Action Shooting, my great respect and a tip of the hat go to Beans, given his very long experience with the sport. He is more knowledgeable of the required power factors than I am and I'd imagine he has won many, many more matches than I have.
All that said, my own loads for 200 gr. .45LC loads are 5.8 gr. of Trail Boss. I vary between the somewhat narrow range of 5.7 and 6.0 - that's just what suits my guns. Like many CAS shooters, I'd imagine, I set a load that is great for my revolvers and then use the same load in my rifle. Having had a squib or two in my time, I like a load with enough recoil to assure me that the train has left the station.
When I don't load with Trail Boss, I use Clays or Titegroup. Tend to do that more when using a buddy's gee-wow progressive press.
As for bullet weight, I load a few hundred 250 gr. bullets, kept in separate boxes, for when the spotters "seem hard of hearing."
Like Beans, though, all that can go wrong with my body is going wrong, so my notes are more retrospective than present-tense, except that I still go to the indoor ranges and fire these same loads from the same guns and am as happy as ever with them.