I recently converted (another) Peabody RF to CF, this time a .41 Swiss.  Pristine bore, 3.5-4.0lb. trigger, overall excellent condition, but not collector grade; shooter grade.
I used the same load in this as I do in the Vetterlis; 18 gr. 4759 under a discontinued Lyman .44 bullet; can't remember the number designation, but it casts out at .432 and weighs 350 grains.  It's a big'un and is at the upper end of stable I think, but...amazing accuracy.
Unless you have an immaculate collector grade rifle, I'd encourage any of you who are shooters to do the conversion.  You'll find these to be amazingly accurate pieces.
Regards,
Timbo

I converted a Vetterli with an exc bore to Cf and made cases from .348 Win brass ,  and its a real fun gun and amazingly accurate .I know bore size varies , but I was lucky that  429 bullets worked well .Should get it out soon and see if I can improve the sights for my aging vision