@Dobegrant Thanks for giving me a name for the guns.
Here are the three Thumpers in their final form:
Left to right: 58 cal 1:38 24" in a Big Boar reinforced stock; 54 cal 1:38 24" in a reinforced WMC stock;
54 cal 1:38 21" in a reinforced WMC stock
All three are Bobby Hoyt rebore with the 21" a reline/rebore
Some surprising specs: Both the 24" 58 cal in the bigger renegade type stock and the 21" 54 cal in the WMC stock weigh the same: 6lbs 10 ozs. The 24" 54cal weighs 7lbs 2ozs. The 58 is a true .580 diameter bore, the 24" 54 is a true .540 diameter bore and the 54 reline/rebore is oversized at .5412 diameter bore. All three have a "kentucky" rifling style as described/illustrated in Ned Roberts book (same as T/C but with a groove depth of .010 for concicals). All three have Williams Ghost ring Firesights I have modified to fit the 1" barrels as they will be hunting guns.
The provisional loads I plan on using with T7 3F powder:
58 cal 510 gr oversized .582 minie, a 580 gr maxi ball, and a 560 gr maxi hunter..I will try a 444gr REAL also
24" 54 cal 485 gr No Excuses
21" 54 cal 425gr CVA Buckslayer
Depending on the results achieved shooting, I have another reinforced WMC stock and a barrel that I will rebore to mount in that stock, but I am holding off for now. It might be a 25" 1:32 twist or a 22" 1:32 twist. to shoot a No Excuses 525 gr. Right now I am leaning towards the 22" (but yesterday it was the 25"...decision will be in the shooting results)
I will post velocity/accuracy results as I get them over the next couple of weeks.