i would say, for a slug gun's range, even a 3 power is overkill. if you go with a standard shotgun scope, at 1-2 power, you are able to keep both eyes open, and target aquisition becomes almost second nature. red-dots have issues all their own (batteries, turning them on/off, some can't take the jump from a warm truck to bitter cold). unless you are really wanting to hit the max range of a slug, i would consider staying with the open sigts, and getting a tru-glo front bead, or similar rifle sights