I didn't get any responses in the Guns forum so I thought I may have better luck here.

Does anyone know if you can get a rifled slug barrel for a Benelli Sport 2?

I did a quick search, including Brownells and Cabelas and I could not find a slug barrel fora Benelli Sport. Only Novas.

I don't know about the Sport, but they do make them for the Nova as has already been mentioned as well as the Super 90 12 and 20 ga, and SBE. If I was to guess, I seriously doubt that they do make a slug barrel for the Sport. I would try asking the question on the Benelli forum or contact BenelliUSA direct.