I could not agree more with Flychamps.
A gunsmith gave me a really cheaply made Belgian 12 ga hammer gun with Damascus barrels.2 1/2" chambers
I have tried to blow the barrels up as an exhibit for my Hunter Safety Classes with no success.
Even with a 2 3/4" hunting shell and a 20 ga shell dropped in first after five attempts, no obvious damage to the barrels.
The mud in muzzle worked well, split back for 4 inches.
Flychamps is on target
Mike