I know a lot of people are going to disagree with me but I'm a firm believer in "You get what you pay for". Especially when referring to optics. Personally, I wouldn't waste the time or money mounting a $70 scope on a heavy recoiling weapon like a shotgun.... Unless it's really a quality scope that you got a deal on with eBay or something. If it were me, I would get a Nikon Slughunter or a Leupold Ultimate Slam and call it a day.
P.S. You only need to post this in one section...