Winning the American West could very well be determined to have been done with a muzzleloader. It was the predominant type of firearm during the century. But, it goes to, define the time period and region. We have had a lot of Hollywood stake our our perceptions. It tends to be post Civil War, and seems to focus on the cattle drive towns in Kansas to California. Jesse James is about as east as it gets - the Missouri side of the Kansas border. That's as far as the rail heads had gotten. The Transcontinental rail wasn't finished until 1869.
As for my comments on the durability of the AR vs a lever gun, sorry to burst any bubbles. Carbon blued steel was already on the way out when the 1911 came into use, and wood stocks were passing away in military use before WWII ended. It is entirely the point that the AR was designed - with much less rusting steel, in a durable finish, and with stocks that didn't need extraordinary protection from the elements to keep them from swelling and rotting. There haven't been military weapons issued since WWII to soldiers for use in the field that have blued steel finishes and choice wooden stocks. They went to plywood.
I can look to my '64 Saddle Ring Carbine and see why. It's the epitome of the the classic truck gun taken deer hunting - pitted finish, cracks in the stock, simulated case hardening mostly worn off. It's never seen a day of combat and looks a lot worse than the Garands and M14's I trained with in the day, much less the M16 I used in Basic.
It's gunsmith level work to take one apart as much as you can the M16 - which I have repeatedly done sitting in the grass after qualification, cleaning it. Try that with a lever gun, in your lap, with no tools whatsoever. There are 20 million prior service soldiers, sailors, airmen, and Marines who have done it. Far more than a lever gun in the day.
And I certainly could take my AR to CO and hunt, it's 6.8SPC.
As for the 1911 being a modern Colt Peacemaker, look around the net - there's a lot of them available, they seem to be popular with more conservative folks who can readily identify with the era, and they are carried in TEXAS. We are talking about the West - and a Texas barbecue is a traditional western event.
We aren't talking polka with accordions. If you live on the correct side of the Mississippi, then knowing about guns, the West, Texas barbecues, and having a sense of history comes a bit easier. You can talk to people who descended from settlers who traveled here in covered wagons, you actually know people who wear the hat and boots and ACTUALLY RIDE THEIR OWN HORSES, much less take them on vacation to ride out west on vacation.
Me, my first trip, I went in a convertible Mustang. A bit more new age, maybe, but there it is. Heritage.
Glad to keep the discussion going, there are perspectives on the West that are yet to be rediscovered. It wasn't all shoot-outs and gun play. That was mostly young drunks fresh into town from a long month on the trail.
Kids are still like that.
(As Tommy pointed out, with his comments about the use of anachronistic arms in shows.)