I had a Burris FFII 3-9x40mm on my Ithaca deer/turkey Model 37 combo.

I took it off, and opted for the new Bushnell trophy reddot, with 4 dial-in reticles in green/red. I find it to be as bright as the gobble-dot fiber optic sites that came with the gun.

I actually don't worry about missing the birds between 30-50 yards, because the pattern opens up to ~24 inches. However, at 20 yards, about 95% of the shotload is the size of a slug, and misses are much more common under 30 yards than ever before because of shot constriction.

I would suggest, if you have good eyesight, to go with fiber optic sights or a reddot scope. The Burris had ~4 inches of eye relief, but the reddot are infinite---they also allow you the opportunity to use either hand to squeeze the trigger...

When the dot is red, the turkey's dead...doesn't matter how or at which angle you look through the scope, only where the dot lies...