RE: KY. long rifle,what to shoot?
Check to see what twist the barrel is - if it is a 1-48", you can shoot sabots out of it no problem. I'd suggest a 200 grain XTP or 200 grain Shockwave, starting off with 70 - 80 grains of FFFG powder.
If it is a 1-66" twist, you'll need to shoot roundballs out of it.