How much powder are you loading under those roundballs?

I have a TC Renegade with a 58cal barrel I ordered from Fox Ridge Outfitters. Its the 1-48" twist barrel. It just does not have the "Big Boar" stamp on it. Same thing though.

I have had best luck with roundballs in it. I did have good luck with some Buffalo Ball-ets and I think the 525gr Hornady Great Plains shot well to but those are no longer made.

Try out some Buffalo Ball-ets in it. You can get them from Dixie Gun Works. I think I was shooting 90-100gr FFG with the Ball-ets. The roundballs like just about any powder charge. I like shooting those the most.

The 58cal is a lot of fun! Good luck and have fun