What is this?

[leclairk]

Borescope picture of a new Criterion barrel. What is it? Just curious for future reference.

 

[PigButtons]

I'm no expert, but it looks to me like 'tear out'. It can happen when the chips are not cleared often enough or if the coolant / lubricant is insufficient. But others here are probably better qualified to answer.

 

[std7mag]

I'm going with Pigbutton's answer.

 

[leclairk]

I'm no expert, but it looks to me like 'tear out'. It can happen when the chips are not cleared often enough or if the coolant / lubricant is insufficient. But others here are probably better qualified to answer.

Okay. Is this an issue I need to worry about?

 

[Bill K]

If it effects the rifles accuracy, then maybe. How does it shoot ? Good groups worked up ? Let the rifle tell you.

 

[itchyTF]

Send the picture to Criterion. They should be able to tell you.

 

[STS]

Inclusion (dirt) in the steel.

 

[KMart]

If you haven't done so, clean the barrel. It may disappear.

 

[Cemetery21]

email the photo to james@northlandshooterssupply.com

 

[leclairk]

This barrel has exactly 30 rounds down it. I’m still in the break in process, following the instructions from the Criterion website. I’m cleaning it with Boretech copper remover, a nylon brush, and patches. From what little I’ve shot with it it seems to be shooting fine. I will reach out to Northland and Criterion.

 

[skeeljc]

It looks like some debris from cleaning. It does not appear to be in the steel.

 

[leclairk]

It looks like some debris from cleaning. It does not appear to be in the steel.

When I get home I will run a new dry brush up and down and see if it makes a difference. Hopefully it does!

 

[skeeljc]

Just push a couple of dry patches through the bore.

 

[Daddymac]

What is the barrel material? I know this sounds stupid, but at first glance, it looks like a plating that is coming off.

 

[leclairk]

Well it’s not junk. I scrubbed it and nothing changed. There’s also a handful of spots going down the barrel. I have a call into Northland and Criterion to see what they think. Few more pics added.

 

[Dusty Stevens]

Thats cleaning residue. See how it shoots. A borescope cant tell you that

 

[jonbearman]

That barrel looks like it was shot? If you look real close it looks as though it was fired and it pitted right at the end of the chamber. Do want dusty says but I would push a couple patches through with decent bore solvent and then dry patch it. Use a nylon brush as well Then scope it and fire it. Was it a pre fit?

 

[Dusty Stevens]

Push one patch thru with carb cleaner on it and itll look new again

 

[JFrank]

A bronze brush won’t damage the barrel

 

[Texas10]

A good fitting bronze brush spun in the throat by hand will dislodge those particles if they are just debris left in the barrel. A nylon brush is just not up to the job in this case. I'd do like Dusty says, shoot some carb cleaner in the throat first and spin a brush. Then have a look.

If the steel had inclusions in the quantity as seen in your pic, there'd likely be inclusions all down the barrel and on the outside too. How does the exterior finish look?