Sabot Round can be fired from a Rifled gun it's just more problematic.
A Sabot round or Armour-piercing fin-stabilized discarding-sabot is a kinetic energy based kill vehicle, basically it's a super fast Ice pick meant to stab the enemy at such speed as to punch through the armor.
the round resembles a Metallic Arrow seated in a cup in a cartridge.
The Arrow or Flechette is made of a high density metal like Tungston or Depleted Uranium and is of a smaller Diameter then that of the gun that fires it. the shoe or Sabot keeps it in line down the barrel and helps cup the pressure behind it to the round accelerates down the barrel. at the muzzle of the barrel the Sabot separates flying off well the Flechette is now stabilized by It's Fins.
Now here come the problems A rifled gun Acts to stabilize a conventionally shaped bullet by forcing the shell to follow grooves cut in the barrel these grooves or rifling empart spin onto a round giving it gyroscopic stability. This spin give a conventional Conically shaped round the ability to fly through the air on a predictable more or less straight ballistic arc.
but As I said a Sabot is a fin-stabilized Projectile. Fins want the round to fly without spin, Riffling wants the Round to spin the two together counter act each other causing the round to
"Wobble" loose stability, Accuracy, Velocity.... UNLESS
you apply a Slip ring. This is a material that sits between the sabot and the barrel lubricating the flight through by preventing something like 80% of the rotation it's more common though on 105mm Armour-piercing fin-stabilized discarding-sabot rounds like the M900 in the US Army but it still emparts some rotation and issues vs Modern Armour-piercing fin-stabilized discarding-sabot rounds.