RE: bullet accuracy short/fat or long/skinny
Theoretically speaking, a longer bullet with an ideal stability spiral would be more accurate, basically because it has a longer horizontal axis upon which it rotates, giving it a better aptitude towards stable travel.
HOWEVER, as with many theories, this one has been proven wrong time and time again...I'm assuming, going out on a limb, that you're comparing a .30-06 or .308 to any of the 7mm mags, in any circumstance, the inherent accuracy advantage going toward the 30 cals by far. As far as any hunting scenario is concerned, I agree with SJ, you'll never notice the difference, nor will your game. In most cases, with ideal spiral rates obtained and proper loads, bullets, and guns all matched for eachother, you'd have a difficult time telling the difference on the range even out to a half mile I'm betting.
Screw the 10 ring, keep them in the zero!!!
"When you tell a fellow to go to hell, you had better be sure you can get him there."--LBJ