It's going to depend a lot on the twist rate of the rifling. A Huntsman is a break open built on their shotgun action isn't it? If so, it should take reasonably heavy loads. Once you know the twist rate and the bore diameter, you can go about making or having made a mould for the correct bullet for paper patching.
Of course once you go through all that, you will still not be able to fire more than one shot without wiping and other than bullet weight you won't gain much if anything. If you are going to hunt with it, a fast follow up shot is a good thing. You will likely learn that minie' bullets or patched balls are faster and work just about as well. But if you're shooting at the range and just want to paper patch for it to see how well you can get it to work, well, that's another animal and should be great fun to play with!
You might check out Accuratemolds.com, Tom has some stock designs for grease groove bullets that would likely work quite well in your rifle if the twist is fast enough. As for paper patch ones, those are pretty easy to make yourself since they can be smooth sided. Or get him to make one if you don't have a machine shop at your disposal.
You could also paper patch minie' bullets, but the only reason I have ever found to do that is if the mould you have is too small for the bore of your rifle. Otherwise just shoot 'em naked, they work fine that way and it's less work.
