Is This A Carbon Ring?

JRock95

FNG
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Borescoped a rifle of mine to check on any carbon buildup. It almost seems that the area where the carbon ring would form looks different depending on if I insert the borescope from the muzzle end vs the breech end. I've attached some pictures. Is this a carbon ring, or just a shadow?
 

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  • Muzzle End with Case.jpg
    Muzzle End with Case.jpg
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  • Breech End.jpg
    Breech End.jpg
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  • Muzzle End No Case.jpg
    Muzzle End No Case.jpg
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That just looks like a dark shadow spot where the neck portion of the reamer stops.


In the picture where you have an empty case in there, a carbon ring would basically be touching the mouth of the case if it were there.
 
That just looks like a dark shadow spot where the neck portion of the reamer stops.


In the picture where you have an empty case in there, a carbon ring would basically be touching the mouth of the case if it were there.
Why would it be touching the case? I've seen it build up like what looks like shown in the picture, that looks like carbon to me?
 
Why would it be touching the case? I've seen it build up like what looks like shown in the picture, that looks like carbon to me?
Not actually touching the case itself. But his picture is just highlighting the taper the reamer cut at the end of the case neck. That’s why it only appears like a ring from one direction and not the other, the shadow.

The actually carbon ring would be like 1/8” wide and extended back to where the brass of his case neck is in that one photo. There wouldn’t be a stainless gap in front of the case neck.

All my barrels are currently clean, but in a little bit I’ll take a picture of a legit one.
 
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