I've put all types and varieties of slugs through my 590, and never had an issue.
Excellent... I've been to their site but didn't see this.Here is a link to an article about your question. Careful though, you might end up spending all afternoon at The Box O Truth website.
The Box O' Truth #46 - Shotgun Slugs, Sabots, and Smooth Bore Barrels - Page 1
Worse than 3" buckshot?I've run rifled slugs only through my 590 and it's run great. Definitely wakes your shoulder up!
I've fired 10ga magnum buckshot, 3.5", 18 pellet out of a single-shot, full-choked H&R...Worse than 3" buckshot?
For years I had only been shooting birdshot for trap/skeet. Then I bought a box of 3" Federal Vital-Shok 00 Buck to test my new Mossberg. That was some strong stuff, and a big surprise to me.
My hat is off to anybody that shoots 3 1/2" buckshot shells.