870 Barrel Defects

Hi all, first time poster, but I've been reading threads on here for years whenever I need advice.

The topic at hand is my father-in-law's 870 Express Tactical. When I was disassembling the gun, I noticed there are small nicks in what I presume is the locking lug groove. The gun is 5 years old and has had less than 250 rounds through it, all of which have been target loads with the exception of about five 3" buckshot loads. The gun suffers from the poor chamber finishing that Expresses sometimes get and will have a difficult ejection (shell stuck in chamber) once it gets hot. I've contacted Remington and they said they would look the gun over and provided us with a prepaid shipping label. The picture of a chamber without the problem is my Express, which is 30 years old and was a gift from my father. I feel bad because I told my family the 870 would be a great home defense gun for him, and it sucks to have to explain away the jamming ("it's just because the gun is getting hot and the brass is expanding...") and now send the gun in for examination. I'll detail how the process goes with Remington.

Does anyone have any experience with this?

I've already polished the chamber on my Express and was planning on doing it to this one as well. I don't think that these defects are contributing to reliability issues, but it is troublesome. I know this isn't a 65,000 psi .300 RUM and I doubt this would contribute to an unsafe condition, but I expect more out of a Remington gun. Maybe I'm wrong to. I was planning on getting my wife a 20 gauge 11-87, but that is now dependent on how Remington handles this.