I don't know anything about mounting a scope on shotguns.LuckilyI can use rifles where I hunt.About Mossberg vs Remington no comparison as far as I'm concerned.Remington 870 all the way.It's a much better shotgun.Some like the Mossbergs.I've had a 870 for many years and never has the slightest problem with it.Actually I have a couple 870's. 1 12gs. and 1-20ga.If it were me I'd spend the extra money and go with the Remington.I'm sure you would be allot happier in the long run with a 870.

Ruger Redhawk