SG, Leupold has a set of rings called "Rifleman" series, they come in low, medium, and high and are $20/set, you can order them from Gander Mountain and their shipping is always free. They are by far the best rings I have found for that kind of money. I mounted 2 scopes on 2 870's last year with them for a b-in-law and his son and they are nice rings. If you are using a saddle mount be careful not to overtighten the mounting screws through the receiver, the action will bind up if you overdo it, and a dab of medium strength LocTite on ALL THREADS. Not trying to be a know-it-all, just been through this stuff a hundred times. And good choice of slugs, Hornady SST's are super accurate and kill well!!Yes, I do have a rifled slug barrel. As for slugs, Hornady SST is what I have been shooting out of the 12 gauge I have.
As for the scope, Im going witha 2-7x33 scope. Need to pickup scope rings now for it also.
Are those rails on the Cantilever slug barrels pretty stought with scope on it then?Yep, they should be fine with the 2x-7x 33mm scope you are talking about getting. Matter of fact, I changed out a buddy's 870 before this past hunting season from a B-Square mount to a cantilevered slug barrel and used the low base rings from the B-Square unit with a 3x-9x 40mm scope and there was still plenty of clearance, so yes they will be fine.