Birdboy

I use a Benelli M2 for dove shooting and I really like it a lot, most of my friends use Remington 1100 or 11-87 and they have all kinds of problems, something always breaks. Anyway I notice that the top and bottom section of the ejection port is being worn by the spent shells, is this a normal feature. I am worried that it will eat away and damage the shotgun over time. Is there anything I can put on it to stop the wear.