I'm not sure how far west "West" is, but I've found a very open right barrel quite useful on pheasants where I've hunted them. That's mostly been Iowa (in a lot of years when we were the #1 pheasant state in the nation), but also the Dakotas and KS. Don't think you'll find any better pheasant hunting if you go any farther west than that.
But indeed, there are variables. If you hunt in a very large group, which often happens on pheasants (especially in SD), shots can be longer. But if your group is small and your dog(s) reasonably proficient, shots are likely to be a lot closer. Some people suggest that shots tend to get longer as the season goes on, but I've had days hunting pheasants in the snow with more in my face flushes than I get on opening day.
As far as writers go, I tend to focus on those with experience. When it comes to how shotguns perform, I certainly put Brister in that category. When he says "I do know that at 25 yards a pure-cylinder barrel will throw one of the deadliest game-getting patterns you ever looked at," (p. 136, "Shotgunning: The Art and the Science") and "Full choke is a demanding mistress; improved cylinder a forgiving friend" (p. 126), I believe him because my experience shooting wild birds bears it out. If you find yourself shooting upland birds at 35 yards + most of the time, then you certainly need something tighter.
Experience can be a bit hard to qualify or quantify. Over a span of 20 years, when I was living in good pheasant country, my average was right around 65 roosters/season, counting wild birds only.
