204 Ruger barrel life in AR-15

[1raggedhole]

This question has been asked many times, but I didn't see much for real life experience with an AR on p-dogs. I have a WOA 204 upper that has around 3000 rounds, mostly on p-dogs. I use temp tape and usually switch rifles when gas block reaches 140 deg, but it has been up to 180. It will still shoot decent (<3/4"), but I noticed during my last trip that bullets were sometimes missing by a long ways when the barrel got hot (even without cooking a round in the chamber).

So, who has real life experience with this caliber in ARs and barrel life? I'm wondering if 3000 is nearing the limit.

 

[1raggedhole]

Last weekend I shot 20 rounds after moving scopes around, and it had significant copper fouling. It was clean when I put it away last fall.
Although I don't have a bore scope, I have one of those cheap micro cameras connected to usb, and you can see dull/rough lands from the throat down the barrel for at least 4".
These signs also worry me. Any thoughts?