My take is the cost of saboted slugs is ridiculous. Smoothbore shotguns have short range.

I have hunted and harvested deer with both rifled and smoothbore shotguns. My recommendation is a muzzleloader and nice scope or a rifle if it is legal.

rifled barrel you can shoot almost twice as far acurately with sabots but they are triple the price and in my opinion depending on what kind you use can have better knockdown power farthest i have dropped a deer with rifled barrel and sabot 140 yds could prob shoot a lil farther but i dont recomend shooting much past 150 its not a rifle. rifled slugs are good too thts what my dads been using for 20+ years so its all in your own preference

You can make a good case for the ML. I bought an 870 combo that came with a smooth and a rifled barrel that I hunted with for a while. Didn't take long and I started bringing my (rather cheap) ML whenever it was legal, which was just about always (we have a few pieces of public land that allow shotguns but not ML's for some reason). Last year, I bought a Savage 220. $200 is a pretty good down payment on a nice slug gun or ML, and you can get a decent ML for that.

I say just get a 220

I have cousins that shoot deer at 100 yds. with smooth bores and no rifeled slugs! Just take your gun and buy 4-5 different brands of slugs, then shoot them to see which one patterns the best! If non of them pattern then you should go buy a rifeled barrel. I had a shotgun that would shoot any slug for crap so I ended up buying a gun with a rifeled barrel 20 gauge Ithica and it's right on at 100 yds. Try your gun first with different slugs!