There's a lot to be said for the Sharps. Paper cartridges can be made. I can't think of it right now but there is a company supplying the materials. Try Dixie Gun Works. As for making your own, contact Mike "Duke" Venturino, in Montana. you can probably Google him.

Now, if I were facing a bear I had just made very mad, I would prefer the brass cartridge of the .45-70. Commercial loads are of neccessity very low pressure, and thus velocity, but safe handloads can be worked up. Again, Mr Venturino can be of help here. He is very much into old heavy caliber black powder rifles. He writes articles which can be found in various gun books and magazines.

Good luck, and let us know what you decide and how it turns out. Stan