My upper’s feed ramps in the extension appear to have been “polished” in some fashion as they are not as smooth as I am used to seeing and they are slightly uneven. do these look okay to you?
Also, does anyone have any idea why the barrel extension has some black discoloration? is that corrosion?
does it feed? If it does I wouldn’t worry about it.
That looks better than my BCM and DD uppers, which I have untold rounds thru without any problems.
If you rifle is working, then don’t worry about it. Just shoot the damn thing. 
As far as the corrosion/discoloration, my rifles are pretty much always dirty, so I probably wouldn’t notice any discoloration or corrosion.
It looks fine to me. The feed ramps are only there to guide the round into position. If it feeds, it’s probably fine.
Don’t sweat the discoloration either.
Is that the same upper that you sent back to BCM for having a (visually unpleasing) canted FSB? If so, I’m writing a book right now you might want to read. It’s titled It’s Not Broken: Or How I Learned to Stop Worrying and Shoot the Gun.
Yours looks better than my Noveske’s ramps and I’ve never had a problem. Runs smooth.
Put some fouling in that gap between the breech face and barrel extension and report back.
Looks good to me too
Very clean in there!!!
Many of your posts seem to focus on trivial or basic stuff and it would seem that some of them could easily be answered by doing some homework.
In any case I think we can call this one closed.