The tracker II is a rifled barrel so you should use sabots in it. The standard 20 gauge sabot slugs are great to 100 and then start falling off not long after that. The high velocity sabots, like the winchester partition golds, are flat out to 150 and then start falling off after that. Knockdown of the 20 gauge win part golds is comparible to factory (remington) 45-70 loadings. But sabots are expensive.
For the shorter ranges you're talking about see if you can find a smooth bore tracker I at a gun show or pawn shop. If you can't find one and have a good gunsmith in the area you might want to buy an NEF Pardner 20 gauge from Walmart for $87 and have the smith cut off the choke and install iron sights, peep sight, or drill and tap the 20 gauge barrel for a scope (12 gauge is too thin by most smiths liking for drill/tap, but some will do it). Then shoot the cheaper 20 gauge 3"mag "rifled" slugs, of which benneke's are probably the deadliest. Then you'd be set to 100 yards and save a little money, maybe enough in your lifetime to break even on the gunsmith deal...
Or you can do what I do, shoot a Parnder 12 gauge mod, $87, bead front, rifled slugs. I've shot cheapo win's rifled slugs in the past but will be switching to bennekes (rottweil) slugs this year. It's my stalk/drive shotgun during deer season. I have an ultra 20 for my deer stands (shooting 3" fed barnes expanders). The pardners modifications as it sits right now, truglo front sight replacing the brass bead, $12, synthetic stocks, $40 (or around that, I can't remember), shell holder on stock, $5. It has a far amount of recoil but you never feel it when shooting at a deer. :wink:
Hope this helps.
later,
scruffy