RE: SCOPE QUESTION
IMO a bushnell banner isn't too great of a scope - for any gun.
But of course the scope may very well fit its purpose and provide years of satisfaction. I have seen very expensive scopes go south w/o explanation just as I have seen inexpensive ones do.
I myself do not like the relief of the bushnell banner scopes - ESPECIALLY for shotguns.
But the numbers you speak of do confuse me. Usually those numbers go higher and higher as the highest number is on the bottom. Those numbers are for distance the farther you shoot the higher you have to aim to place the bullet on target.
But 20 - 600 yards on a shotgun scope?!