Please will people who ask questions like this give some detail. What is the gun ? A purdey? A Parker? A Ugatachea? O/U or side by side?
Apart from that the man who told you "pinging the barrel lump " is no gunsmith . When the bites on a gun wear the lever can come past center ,it could also be that the spindle is worn or that the lever itself is worn . It could be one of several other things ,but without knowlage of the gun every thing is a guess.