I would not shoot it . Depending on the cost and the make of the shotgun ( you don't want to over capitalize it ) I would get some one who knows about soldering barrels together , or ribs on barrels , to have a look . It is not too hard to do if you know what you are doing but you must know what you are doing .
When I was 11 my neighbor asked me to shoot his wife's cat when they were in town ,so he wouldn't get the blame for the cat disappearing and lent me his recently reconditioned hammer12 ga ,double . I shot the cat with 2 shots just because I had 2 shots and the barrels fell apart .There was a considerable amount of rust between the barrels .