RE: shotgun scope size
The Nikon 2x7 32mm is a great scope. A buddy has one and I have shot his gun. Nice... Also worth a look is the Leupod 2x7 33mm shotgun scope. A touch more eye relief and a few bucks cheaper. It has a heavy duplex reticle which I like for picking the crosshairs up quickly in heavy cover but some think it blocks the target somewhat. I also like the 32mm or 33mm objective. The 20's are just too small effectively preventing some light transmission.