Any shotgun that is in a safe and operational condition CAN fire a slug. But, and this is a BIG BUT, you need to know what the choke/constriction of the barrel or choke tube is. I primarly use my shotguns for upland game and waterfowl. I have one dedicated turkey hunting shotgun. The turkey gun is a browning BPS 10 ga 3-1/2" chamber with Invector choke tubes. The tube that stays in that BPS is an Extra Full Turkey extended and ported, lead shot only tube. Could I shoot a slug through that tube? Yes. Would I shoot a slug through that tube? No. The constriction on that tube is so tight that accuracy with a slug would be non-existant. The few times that I have hunted deer in a shotgun only zone I have used the gun with the most open choke I could find, a Mossberg 500 with a 20" straight cylinder barrel, aka no choke at all. As far as what type of slug to shoot goes, if your barrel is rifled you need to shoot a sabot slug. If the barrel is non rifled you need to shoot anything BUT a sabot slug, AKA a foster type slug. Hope this helps.
Class III
