Crio rifled choke tube?

[wud duk]

Why is there no rifled crio choke tube for shooting sabot slugs? I know you can get a rifled barrel but a rifled choke would be a much cheaper alternative. Does anyone have a link to an aftermarket choke that will work?

[muzzleloader]

I had a rifled choke tube for my Nova...about 6 inches long past the barrel. Bead sights and slugs did not work out for me. I have to have the bead cover my target to hit. Choke was all black, thick walled, like 50 bucks. Sold it to a gun shop for 15 bucks. As for maker I do not rember, came in a clear plastic tube with some paper inside and hung on a peg hook in the store. No clam shell packaging or big frame around it, like a single cigar hanging.