More like 2,500 rounds, not 500.
At that point the tube can be relined and rebored, restoring the rifling.
This means disassembling the gun and returning the tube to the foundry.
Not a simple process.
Thanks. I must have been thinking of WW-II era barrels.
Never-the-less, I would think that in in heavy continuous fighting, those 2500 rounds would happen fairly quickly.