I have read (and this may be a crock) that in trade with the Indians a firelock would placed with its butt on the ground and traded for a stack of beaver skins equal to its height. That would encourage long barrels, at least in trade guns.
We should also consider that much of what passed for design 200 years ago was really copying tradition. Nobody had a chronograph. There were a handful of eprouvettes for testing powder and the odd ballistic pendulum in a royal armory. Most craftsmen were just looking at what their masters had made, who in turn were looking at what their masters had made.
Don't underestimate the possibility of greed multiplied by tradition.
Its a crock. The NW gun went for 20 beaver skins all through the trade era. Hansen discussed that myth in his book on Trade Guns. Like rifles the NWTG had a longer barrel in teh East and a shorter one in the West. This was the gun the Natives liked to use running buffalo on horseback as it could be loaded without a patch. They also burst a few barrels doing so. The Natives probably believed in advantages of longer barrels just like the whites did.
DP
