Not the same part but they're basically identical except that the rifle sight has screw holes in the base to be screwed on to that rifle barrel, and the slug barrel has the rear sight brazed/soldered onto the barrel, no screw holes.
I have an 870 slug barrel and an 1100 slug barrel with rifle sights and both have the rear sight soldered on, I don't believe the barrel is thick enough to allow the sight to be screwed on.
If you're talking just about the aperture slide that goes onto the base, they yes, they should be identical for either rifle or shotgun.
Last edited by Wink_man; 03/10/13.
