Most slugs are totally fine. if you examine the box they tend to say something like
"The incredible efficiency of this rifled slug permisit to be fired out of a smoothbore or rifled barel, in any choke configuration without decreasing it's incomparable accuracy and stopping power"
that was off a box of Challenger 12g 2 3/4" magnum slugs. The spelling errors and improper sentence structure are lifted right off the box, it is a Quebec company, I assume the errors are translation based. Remington Slugger says "Safe for use with any Choke."