In the part of MN where I deer hunt, slugs are mandatory (roughly the lower SW 1/2 of the state. More generally, the non-forested, farming part).
I use a 12 gauge synthetic Beretta AL390 with a Hastings fully rifled slug barrel. I have a Leupold/Gilmore red dot sight, and a two point quick sling. It's nice handling; very fast to shoulder, acquire and shoot.
I shoot Federal 2 3/4" sabot slugs. I've never used 3" shells, as 2 3/4" shells seem to work just fine, and 3" shells just make more noise and recoil.
At 50 yards, it easily shoots 3" groups from a sitting position with a sling. I've never shot paper with it from any further than 50 yards.
I've been using this set up for about 9-10 years. I've taken probably 12 deer with it, ranging from maybe 90 yards to maybe as few as 20. A few have been knocked off their feet, onto their backs, legs kicking. Most have been DRT. Never had to track any more than 40 yards.
-nosualc