The Museum of the Fur Trade Quarterly Vol. 44 No. 1 has an interesting piece of correspondence from Alfred Brunson the Indian Agent at LaPonte, WI dtd. January 10, 1843 you might find of value. The relevant part is this. "The guns heretofore sent them are of the poorest quality & often burst the barrel or break the lock in a wee after being in use. These poor things are stamped "Leman, Lancaster, Pa." and "Darenger, Phil." Hundreds of them are now lying useless, or being wrought up by the Smiths into some other article. The old North West English guns are the only kind that can stand them. If Americans cannot or will not make their goods as good as the English, let them keep them, & not impose them on the Indians."
If nothing else this might provide you with an idea of what not to make.