Thanks Jevyod - nicely done! I have a trial ready using IMR 4198 and Cast Performqance 420's - 35 grains up to 40.5 in .5 grain increments. I recently got a Prochrono, and will be chronying them this week. Once I get an idea from this, I was going to keep the same range of charges with my own cast boolits, in 425 grains. I'm doing some digging and think I'll be giving either Ben's red or Ben's blue a try. If I can find a way to crimp/seat the gc's without a sizer, that is. One place (probably here) mentioned just applying a very thin coat of grease and using the Lee to seat the gc, then pan-lubing and go. Unfortunately the Lee I have coming is .460, and even though my bore is .458 and this .460 should work (I think?), I wouldn't mind having that extra little bit from using an alloy other than the wheelweight.
Thanks for the encouragement - and indulging this noob, lol. Just don't want to bore you experienced shooters to tears!