I know with me, and my poor right eye, I get 3" groups at 50yards open sighted, and about 5" open sighted at 100 yards. Both these are from modified field positions like a rest from a good tree or my rest from my tree stand.

Now put a scope on that same gun, and I am hitting 1" at 50yards and 2" at 100 yards.

Thats with a 870 express and ammo I know works pretty well. All I have on my gold slug gun is cantilever, so couldn't tell ya.