Last year I used the cheap Winchester Sabot slug that WalMart sells. Plenty good enough for shotgun ranges. For longer ranges, say out to 125 or if you're REALLY lucky 175, you'll have to do a bunch of testing to see if there's a slug your gun likes. I liked Hornady SSTs but never had a gun that would group anything well beyond 100.
Still happily answering to the call-sign Peetza.
You do not HAVE a soul. You ARE a soul. You HAVE a body.
He is no fool who gives what he can not keep to gain what he can not lose.
-Jim Eliott, paraphrasing Philip Henry.