RE: 54 cal. Test Drive
My New Englander likes 80 grains Pyrodex RS under the 385 grain GP's - but they are not really tight in my bore. The rifling only cuts the top driving band. I've never used felt wads under them, but it seems to work real well for those who do. You might want to try some if you have any. What powder are you planning to use?
EDIT: Wait, I'm confused. Are you going to be shooting the .50 or the .54? I looked on the Honnady site and don't see any 385 GP in either caliber.