There are Damascus barrelled shotguns out there that have been pressure tested to handle the loads. You can have a gun pressure tested as well. However if it failed you could have a worthless gun. While you could use blackpowder loads in the gun and have some historic fun with it as well. Do some search on vintage shotguns and the Vintagers. They would be able to point you to proof houses and give you way more information than you ever wanted. Remember, you are trying to do something that the gun was not built to do. It may be able to, but it may fail. Don't be a test dummy!!!