A very nice looking gun. Investarms makes Cabela's, and Lyman Hawkins and other such rifles. The 1-48 twist will work real good. All you need remember is with that short barrel do not push it too hard as it really does little good.

I would start the rifle out with 70 grains of 2f powder and a patched ball. If you have some conicals around, try them as well. I bet it will be a good shooter. Its a real nice looking rifle.