I've shot the Nikon VSD (variable size dot 1/4/6/10 MOA) on two different turkey guns for about 15 years and start the early morning w/ a 1 MOA dot w/lower light intensity and crank it up to 4 MOA w/ higher light intensity when the sun gets up and it gets light. I think that a 5 MOA would be fine, and although I have the ability to utilize the 6 or 10 MOA have found that I don't need a dot that large even on the brightest days, especially since the large dot MOA occludes so much of the gobbler at close ranges.
