What is this?

[leclairk]

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?

Exterior is smooth as a baby’s butt

 

[Texas10]

Both Criterion barrels I've purchased, a 223 Match and a 6BR where both beautiful on the inside and out. Nicely lapped finish, perfectly symmetrical leade, unmarred external finish. And both shoot as well or better than several other custom barrels I have.

 

[Dgd6mm]

Both Criterion barrels I've purchased, a 223 Match and a 6BR where both beautiful on the inside and out. Nicely lapped finish, perfectly symmetrical leade, unmarred external finish. And both shoot as well or better than several other custom barrels I have.

Same goes for mine.

 

[leclairk]

It’s disappointing that a hand lapped match grade barrel would have anything in it. I shouldn’t need to scrub it with carb cleaner.

 

[Dave Way]

Are you shooting coated bullets?

Dave.

 

[leclairk]

Are you shooting coated bullets?

Dave.

Nope. Hornady Whitetail. I’ve got match ammo once I’m done breaking it in.

 

[leclairk]

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

I have brake cleaner, would that work?

 

[Dusty Stevens]

I have brake cleaner, would that work?

Yes just not as good. Every cleaning kit needs carb cleaner. The cheaper the better. I get a deal on it at napa. Just keep it away from plastics and any gun stock finish

 

[leclairk]

Yes just not as good. Every cleaning kit needs carb cleaner. The cheaper the better. I get a deal on it at napa. Just keep it away from plastics and any gun stock finish

Dusty you are a genius! I ran some brake cleaner through it a couple times and it’s clean as a whistle. Thank you! I owe you a beer.

 

[Dusty Stevens]

Dusty you are a genius! I ran some brake cleaner through it a couple times and it’s clean as a whistle. Thank you! I owe you a beer.

Now youll know what youre looking at with a borescope. It makes stuff look real bad sometimes

 

[leclairk]

What do you clean out the carb cleaner with?

 

[Riesel]

I'm putting a big like on this because the problem was solved. Good show Dusty and leclairk

 

[Big Mc]

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

Isn,t a bore scope great. Tommy Mc

 

[shoot4fun]

Isn,t a bore scope great. Tommy Mc

Really?
That borescope kept him tormented for several days.
Over something he never would have seen without the scope.

 

[Dusty Stevens]

What do you clean out the carb cleaner with?

Nothing. It will dry in about a minute

 

[leclairk]

Really?
That borescope kept him tormented for several days.
Over something he never would have seen without the scope.

I have had the very same thoughts!

 

[TAJ45]

Isn,t a bore scope great. Tommy Mc

Hey GUYS ! He was being A. Facetious. B. Tongue in cheek C. Kidding

 

[shoot4fun]

Hey GUYS ! He was being A. Facetious. B. Tongue in cheek C. Kidding

I pick ABC!
LOL

 

[coldboreshot]

I've always said, borescopes and chronographs should come with psychological disclaimers.