I had a red dot for many years (10?) on my 12ga. All of my slug season deer have all been within 80 yards; no need for magnification. It was lightning fast on target. Nothing better for jumping deer.
Last year I had problems with it holding zero, and replaced it with a 4x Leupold traditional scope. No need for big magnification or the complexity/cost of a variable, and the simple scope should hold up to the recoil.
I kinda miss that red-dot tho.
Although the 20ga does not have a much recoil as a 12ga, my advice would be to get a scope with a ton of eye relief. It's easier on your eye-brow.
-nosualc
Last edited by nosualc; 06/07/09.