there is very little practical difference in a big game rifle that shoots 1" 5 shot groups and one that shoots 1 1/2" 3 shot groups.

That is only partialy true, hunting in areas that shots are made within 200yds, yes!, over 200 you need better groups to be confident. Now I'm not wanting to start another ethics blow-out on how making 500 + yard shots is unethical, I'm just stating that if you hunt long range, you need a rifle that can handle the task, if you happen to have a rifle with a long throat and you want to get every bit of accuacy out of it, your better off to re-barrel instead of setting back a stock barrel.