I doubt it will hurt it, but it will serve no purpose what so ever. Unless you like cleaning your barrel alot. And I am talking soft lead shot, DO NOT use heavy shot, steel or any of the other harder shots they make, you could possibly ruin the barrel.
And a rifled barrel has no choke, so the shot will not pattern at all. Imagine cutting 3 inches off from your bird barrel. You will get about 3 foot patterns at 10 yards.
I will fire field loads some times to test the weapon only because they are much cheaper than saboted slugs. However they will not shoot well enough to serve any other purpose than testing whether the gun functions or not.
I am not a gun smith though, if one tells you not to do it I would listen.
Paul