Schematic for Berettaź 92A1 / 96A1 - World's Largest Supplier of Firearm Accessories, Gun Parts and Gunsmithing Tools - BROWNELLS
I'm not a gunsmith, but, it looks like the ejector no# "32" in the schematic from Brownell's is making the mark along the side of the case. If the firearm is cycling properly I'm not sure scratching the case is a problem nor the mark the extractor claw is making on the rim of the case. But, If you take the slide off and insert a round into a magazine and insert the magazine the ejector no# "32" should ride parallel, just left of the casing but not touching. Being a used pistol I'd check to see if the two pins; "33" and "34" are there holding in the ejector or perhaps the ejector may be damaged and need's to be replaced. I'd run it by a reputable gunsmith and ask him/her if this is a problem that needs fixing.