Re eightbore - this is no surprise. Before the Trans-Siberian railroad was completed, everithing that was supplied to easternmost parts of Russia (e.g. Vladivostok) had to travel about 6000 miles on hirses and rowboats. It was naturally faster, cheaper and easier to sail to 'Frisco, even after the railroad was operational.
The area at that time had only a handful of sportsmen, and a large crowd of market hunters. And the only market game that required the use of a shotgun was waterfowl. Needless to say more, not at this forum ;-). As for printed evidence, Gen. E.T. Smirnov, in his 1901 book "The Hunting Shooting", states that the most hot-selling shotguns at the Russian Pacific coast at the time were the Winchester repeaters.
Re Lowel Glenthorne - quoting the above-mentioned book: "... the people for which hunting is everyone's domain, the people who never knew the fuedal barons that would hang a man for a killed partridge..." ;-)