multi caliber

Well, I finally pulled the trigger on a 22 can. I am getting the dead air mask HD 2. I am super excited, and must admit I'm already planning my next suppressor. I've heard of 30cal cans that can be used with 308 etc, and 9mm (with a booster of course), is this true? Can 9mm be shot out of a...

Do any of you guys or gals have any experience with those caliber specific inserts for break action shotguns? Like the rifled adapters that fit into the chamber? How accurate are they in your experiences? Are they worth getting? It seems like they'd be a great addition to a shotgun trunk gun...