I have a mossberg slugster 20 gauge in realtree camo with a truglo red dot scope. The setup is about 4 yrs old now. My question is there anyone who has had good success with a certain slug in this particular gun. I kind of lean toward lightfield sabots. Any help or suggestions would be greatly appreciated. Also some opinions on the truglo red dot please. Thanks in advance

Lightfields and a truglo should be more than the ticket for successful whitetail hunting. Are you having problems with grouping or something else that causes you to ask that question?

I have the Trophy Slugster with cantilever mount and a 3x9x40mm scope. IT LOVES FEDERAL BARNES EXPANDERS!!!!!! Shoots Winchester Platnium Tips pretty good as well. Shot various different brands and configurations. Mine didn't like Lightfields.
So far as on paper, I haven't found that it prefers 2-3/4" over 3". Deer don't seem to notice a preference of one over the other either!!!!!

Try the Winchester Super X 2 3/4 BRI.

Just went to the range today with a relatively new Savage 220. Tried out Hornady SST's, Rem Accutips, Federal Copper whatevers (new round, I think), and Winchester dual bond (first 2 in 2 3/4; last 2 in 3 inch). The SST's performed the worst, didn't group well, the others all performed well enoiugh, I'd say the Accutips were best (but I've heard they have penetration issues??), The Winchester's probably next.

I also have an 870 with a slug barrel (12 gauge) that SST's didn't perform well out of. Performance improved dramatically with Rem Copper solids, which are a much slower round than the SST's. In my opinion, if you are having grouping issues, try a slower round.

This summer I shot Remington and Winchester 20ga 2 3/4" slugs, in my savage 24 smooth bore. Remington would have killed deer and hogs, but were all over the place, covering
18-20". The Winchesters shot a triangle with the same point of aim over factory sights. Even though it's tough and expensive, to find, try different ammo to see what works.

3" remington accra tips work best out of my 220 savage & my 20 ga encore & no never had a issue with penatration all deer were drt furtherist traveled 10 yrds & ranges were from 20 yrds to 180 yrds