Rico, because I wouldn't shoot at a deer at 40...but I'd shoot at an elk at 40 because a "pie plate" is well within it's vital size. In my experience, limited though it may be compared to some, if you are shooting say 4" groups of 4-6 arrows at 20 yards, you more than likely will be shooting maybe 6-8" single arrow groups at that same distance under the pressure of live big game...at least for ME that holds true.
For me, there is no comparison in the pressure between shooting foam, even in a big tournament, and shooting live, breathing, moving, "about to bust you and blow out of there" big game. In my humble opinion, the ONLY way to get better at shooting big game is to spend a lot of time in bow range of big game and shooting big game. Until I feel as confident on big game as I do on anything inanimate (and small game), I personally will stick to an ever increasing, very high standard of accuracy. And then, even if/when I do become that confident, I'll still probably stick to that same level of accuracy because I know it is not a dream...it can be a reality. It just takes the appropriate mindset, appropriate practice, and appropriate equipment. Your mileage may vary...but it works for me.
Otto, at the level I require of myself I find it very difficult to concentrate for 12 arrows. Typically, if I shoot groups at long distances it's 3-6 arrows. If I'm not mentally spent after 6 shots in a row, I'm not concentrating hard enough. Again, ymmv.
Rod, coming from you, that certainly means a lot. You have been instrumental in helping me stretch outside of comfort zone in attaining accuracy I previously thought unreachable. Many thanks for your example and advice.
Jason, from what Charlie says about you, I'm sure you and my Grandfather would have got along famously. Hope to share a camp with you someday.