Oh.....
For an 8 bore bullet rifle I would go faster than 1-48
I would recommend about a 1-26. You can still shoot balls, but you would have to clean it after every 2-3 shots. But you can shoot bullets of about any practical length in it. Up to about 1000 grains.
Make sure that the rifling is about .006 or .007 deep for bullets. If a "ball only rifle" I would go about .009- 012.
To fire balls in a "bullet barrel", you need to have a patch of about .012" and a ball of only about .005 under bore size. If you load with a lubed felt wad under the ball you can expect very good accuracy.