Dents in the necks of every piece of brass

[FOGeologist]

I fired 100 rounds at 200 yards a month back and had some really, really terrible results - first round flyers 9" to the right. I decided to anneal the brass after tumbling it and I noticed while annealing that...

Every case had two nasty dents in the neck. There were long scratches that were much more apparent than before I annealed cases.

I think Faxon may have sent me a "Monday after a holiday" barrel with an exceptionally poor chamber.

I wish I had considered this more carefully before I inserted this barrel into my new upper yesterday.

[edgecrusher]

That’s not that bad bro… what’s your round count on the rifle? 

[jtallen83]

Looks pretty normal, just smooth it up with lots of ammo.

[FOGeologist]

You guys may be on to something... I have perhaps 140 rounds on the barrel.

I also pulled out primers that had been hammered into the bolt face - it's possible (probable) that there was a piece of brass or grit stuck in the chamber area that got scrubbed out when I took the barrel out of the upper receiver and hosed it down aggressively with spray cleaner and put a chamber brush in a drill and burnished the chamber for a bit. (No, I didn't do any damage to it)

I have a cheapo borescope on the way to see inside the barrel so I can confirm my chamber and gas port look good.

[dpete]

Those look like fang marks from the feed ramp edges.

[jtallen83]

^^^ Yep, bet they line up with the extension ramp lugs.

[FOGeologist]

You guys are both right.

My new borescope reveals a barrel and chamber that are pretty great.

gas port hole. A touch of erosion going forward.

[dpete]

Another mystery solved!   Dun Dun Dun     <--mystery movie sound effect