Why only America, buzz? The trends you're speaking about are true for the whole world as far as I know, and for a good reason - as old Hem said, all hunters are the same people.
And it just dawned on me that hunting is, in principle, the quest for the new. Finding one most successful routine and sticking to it works fine for agricultural society, but it is a bad survival strategy for a hunter/gatherer. Very soon you've picked up all roots and mushrooms, killed half of the game, and the other half has adapted to your pursuit, and you have to move on to the new grounds or devolop new skills and tactics - or else.
If this is true, then it is in the nature of hunters and hunting to always want something diffenent, for difference's sake. That's why a 'new' gun, ammo, breed, clothes will always sell even though the 'old' stuff works well enough - but also why small bores, vintage doubles, muzzleloaders, bows, falconing, ferreting, and so on, remain - because someone will always want to try something new, even if the 'new' is nothing but a well-forgotten 'old'.
To think of it, that's probably why the hunting instinct hasn't been evolved out of our genes yet - because this relentless quest for the new is directly associated with Invention, our best and most powerful survival tool.
