In looking again, I found one note on of the smooth rifle notations.
on page 267: notes by Henry Boller- around 1858, a note to his father (back East) from the Upper Missouri
after several months:
"a gun according to the following description. It is the proper kind of gun for this country. A light, double-barreled gun -- barrel 26" in length'
small caliber, to carry accurately the trade (or half-ounce) ball. (.52-.54cal. - my note). We don't use much shot up here, but a gun of this kind
shoots either ball or shot well. Rifle Stocked (wood of black walnut, greased,not varnished) with a large breech box, easily opened; 2 sights
on the barrel like a rifle, plain & to catch a quick sight through; locks of the best, and most substantial kind; 2 extra nipples. The gun to be light
and strong, and mounted with brass. Such a gun is handy and useful, on horse or on foot."
Sry- still cannot find the gun "order" I was looking for.