Rather than run the expense of sending it to a gunsmith, can I just saw the barrel ends off at home ? or will I also need to have the barrels re-proofed?
For your own safety, I suggest an urgent visit to a good gunsmith.
The cause of the damage would have been huge and dangerous pressure within the barrel, which could have weakened it throughout most, if not all, of its length.
Accepting that the undamaged part of the barrel remains sound, the damaged part can be cut off, but the removal of any metal from a barrel requires re-proof.
Cutting off the two inches at the muzzle will also remove most of the choke area, but multichoke tubes can be fitted.
From the above you will gather that this definitely isn?t a DIY job if the gun is to remain safe.
However, you can do what you like to your own shotgun barrels, as long as you don?t shorten them to less than 24 inches.
The provisions of the proof regulations only apply if you choose to sell the gun.
The laws are designed to protect the buying public and you can risk blowing yourself up if you like.
However, common sense dictates the cautious approach.