I load in my thunderhawk 80 to 85 grains ;I still use the number #11 caps with the t/c flame thrower nipple.I have taken a few deer both with the buffalo SSb 375 Gr. bullet sabot,also used the precision 300 Silver lightnings ,and the precision QT'S 40 in 325 Gr.
I can say I never had a deer take more then a few step with 80 Grains of triple 777.
I like the thunder hawk only because the overall weight and a great woods carry all day long M/L
The only draw back I find in the breech plug not removable.
I once has a base mount screw that would not unscrew seem the crud from shooting black powder sealed this tight as a drum.I could of drilled it out and re-tap the thread .I did spend $7.00 bucks and return it to t/c with a small note
I got the gun back in less then 10 days repaired and they did install a new base mount and screw(great service) what more can you say