Don't know about the "whys " or " how comes " , the only fact I can relate to is my own personal experiences. That being said , I can shot my 4" redhawk at 25 yards all day and do well. I stretch it to 75 yards and my shooting begins to get iffy......Same with my 2 1/2 inch 686 , close range it shoots really well, start stretching it , beware....with my 44-
9 " SRH , with irons , along with my 454 SRH , 71/2 " loaded with 45C ( again with irons ), 50-60 even 75 yards are acceptable. I'm speaking open sights , off hand, with a two hand hold, I'm figuring it has to be the barrel length , hence my opinion...long barrels are better shooters in general at longer yards. I'm sure there's those of you that shoot every day for several hours a day, that will argue the point, but I think that is a fair statement. For hunting , I'd say buy a 6-71/2........personal protection, 21/2 to 4 ....Good shooting !