AAC 300 Blackout Suspicious Barrel

[warrlac]

I purchased a complete 10.5 inch AAC 300 Blackout upper receiver from someone on Gunbroker a few months ago. (Probably the worst GB purchase I've made btw). I broke it down yesterday so that I can insure that it will have been put together correctly (by me) before range testing.

I'm not at all happy with the barrel. It is pretty scared up and has what looks like a grinding wheel cut between the set-screw dimples at the gas port. It also has a couple of gouges near the chamber area. Has anyone seen this kind of damage occur and if so, what would have caused it? The guy I bought it from lives right next to Redstone Arsenal and I'm wondering if he may have done some dumpster diving?

Grind Mark on Gas Port

Bad Barrell

Grind Mark on Gas Port

[Ghost]

Does the cut for the gas block look like it may have been done with a drill press? I'm guessing it's from a pinned gas block such as a Geissele bomb proof installation.

https://d3cfki0l5o2ps6.cloudfront.net/media/files/super-gas-block-ai.pdf

The gouge marks may be from whatever fixturing they used to hold the barrel while either drilling the gas block or tightening the barrel nut. Do they look like vise marks at all?

[grimbeaver]

I would have a hard time bringing myself to use that barrel. What was the condition advertised as when you bought it?

To go along with your theory I have to wonder if maybe the scribble on the barrel is the initials of the guy who disassembled it for disposal.

[JJ]

Does the cut for the gas block look like it may have been done with a drill press? I'm guessing it's from a pinned gas block such as a Geissele bomb proof installation.

https://d3cfki0l5o2ps6.cloudfront.net/media/files/super-gas-block-ai.pdf

The gouge marks may be from whatever fixturing they used to hold the barrel while either drilling the gas block or tightening the barrel nut. Do they look like vise marks at all?

+1

That is for a cross pin gas block of some sort. Not uncommon to see barrels with dual pin cuts, that are takeoff that had an A2 fsb.

[warrlac]

I would have a hard time bringing myself to use that barrel. What was the condition advertised as when you bought it?

To go along with your theory I have to wonder if maybe the scribble on the barrel is the initials of the guy who disassembled it for disposal.

Ha!

No, it was advertised as NOS. When I got it I could see that the feed ramps were copper colored and the barrel was dirty. Definitely not NOS. (And by the way -- The guy is no longer listing on GB).

Thank you for the quick feedback MNGT!

[Ghost]

I would have a hard time bringing myself to use that barrel. What was the condition advertised as when you bought it?

To go along with your theory I have to wonder if maybe the scribble on the barrel is the initials of the guy who disassembled it for disposal.

Ha!

No, it was advertised as NOS. When I got it I could see that the feed ramps were copper colored and the barrel was dirty. Definitely not NOS. (And by the way -- The guy is no longer listing on GB).

Thank you for the quick feedback MNGT!

If you can't return it, I wouldn't be worried about using it. Too bad people are so careless with their builds.