rfisher: I have a thunderhawk 54 cal. by t/c same gun except for the saftey
First let me say the firehawk and the thunderhawk here are 2 great inlines/
I have loaded 120 grains of pyrodex select with the Hornady xtp 240 grain bullet/sabot .I never had anyproblem with the load .
I now shoot the thunderhawk with 85 grains of Goex 3f real BP and 375 grain SSB Buffale bullet/sabot:Both loads are tack drivers.
I use no#11 RWS 1075 + plus caps and have to say with a t/c flame thrower nipple the gun has never had a misfire