Chrome lining flaking off.

[One More Time]

This is an unfired 14.7" FN barrel, PSA upper.
Not just a couple of spots but all throughout the barrel.
I was checking the gas port alignment, which was fine but it looks like the plating process didn't go right with this one.
Got an RMA and it's going back, if the replacement looks like this one I'll just get a refund and be done with it.
Sure don't look like my CL .308 barrel that has around 1,000 rounds through it.

[markm]

I agree that doesn't look so good. That's for sure not copper streaking from test fire?

[1168]

Maybe copper. Maybe not.

Borescopes don’t mean shit. I use mine for funsies, but a barrel that looks like ass can shoot great, and one that looks good can shoot poorly. My favorite thing to do with mine is to look at erosion in worn out barrels.

[One More Time]

Doesn't look like copper fouling.
Looks thin and flaking, but bore scopes can be misleading.
It doesn't look like my other one either that's been shot a few times.
The patches I pulled through it came out pretty clean too.

Short video.

[markm]

I've read here that chrome lining does not flake off like bumper chrome. I tend to agree with 1168. If a barrel shoots, I don't really sweat what it looks like inside within reason.

[tomme boy]

That is not flaking. It is copper fouling. Use a cleaner that dissolves copper and let it sit with it in the bore. I use the foaming bore cleaner and let sit over night.

[HKGuns]

Doesn't look like copper fouling.

Then you have zero clue what Cu fouling looks like. That looks EXACTLY like Cu fouling becuase that is EXACTLY what it is.

[One More Time]

You're right, it's nothing to be concerned about.
I should have known better.
When it gets a few rounds through the barrel it will most likely look like my other one.

Sometimes I need to just keep the spaz in a box.
I am glad I asked though, would have felt like an ass for sending it back for no reason.
And this is the place to ask those sort of questions as the members here are are pretty knowledgeable on these things.

[1168]

That looks EXACTLY like Cu fouling.

Yeah, I think so, even though the color looks slightly off. But that could be a difference in our scopes/camera/screen. I’ve only ever had one borescope and no professional training with it, so I’m no expert. The pattern certainly looks like copper, though, and its close enough to what I’m used to in color.

I wouldn’t bother trying very hard to clean that, unless it shoots poorly. Thats not a lot of copper, IMO. Getting it cleaner than that is in the realm of diminishing returns.

[sinister]

It's a rifle barrel. They start to wear with the first round you fire. It contains a huge amount of heat and pressure.

Why are you worried about it? It's not a match barrel.