I'll be getting an Aimpoint for my 480 Super Redhawk. None of the local stores have any in stock so wonder which size would be best for my use. Choices are a 2 MOA and 4 MOA. My concern with the 4 is there would be too much coverage for target shooting at 100 yards. My concern with the 2 is that target and game acquisition will be difficult. In 25 years of hunting I only shot at a running deer once because it was only at 10 yards. Anyone have experience with either size from any manufacturer?

Target shooting and hunting are two different applications. IMHO 2 MOA is too small. 5 MOA would probably be a good compromise. You can always shoot a larger black bull at 100, although for 100 yards you would be better off with a scope and crosshairs.
Peter.