Whole different ballgame, Chas. A gun that throws slugs well (and, few doubles will do that well, unless they were built up as slug guns) may or may not throw patterns to where you are looking.
The slug guns built up by the Bruchet's had a bunch of work done on the barrels to get that to happen. My brother slug hunt with a Savage Fox model B (the cheapie) that consistantly puts the right slug on a pop can sized target at 50 yards-the slug in the left barrel goes, well, some where.

Best,
Ted