IF you mean an actual scope (as opposed to a non magnifying red dot or the like), the front sight will "disappear" when viewed through the magnifying scope.

Otherwise, most red dots and holographic type sights offer mounts to co-witness , either lower third or absolute (in sync with the dot.) You sight in the red dot then adjust the sight to match the zeroed sight.

1-4 powered scopes are ideal for three gun type shooting and good all around units out to about 200 yards or so.