I'll play.
I'm a fan of H110. I find it works well with jacketed and lead, but must also specify that it works with Beartooth Bullets. I have not tried it with ANY other Mfg. lead bullets.
I drive 265's and 300's over 1000fps in my .45colt blackhawk and Winnie trapper, with absolutely no leading of the barrels.
I have loaded some .357mag with it, and used a 132 grain lead SWC. I used the data for a 125 grain.
Again, no leading [and no GC] I do not know the Mfg .of the bullets, or the hardness, but if I had to guess, I'd say someone made them....not commercial.
I've pretty given up on jacketd bullet reloading too, except for my 9mm, 45acp and .40
The best idea I could offer is to do exactly what you wrote:
Experiment with some loads, say five or so of each, so you do not waste alot of good hard lead bullets!
Good luck.