Scoring of brass and bullets. Burr in the Chamber?

[StumpyJohnson]

Would you be concerned about this?

See pics.

When I chamber a round I get scoring down the bullet and onto the shoulder of the case. The score marks align, and I'm loaded .035 off the lands. The fact that it extends down the case, it points to the chamber, I'll pull the barrel to check.

That said, would this concern you?

 

[nksmfamjp]

Do you have a borescope?

 

[StumpyJohnson]

Nevermind, fingered it out. Not concerned.

 

[StumpyJohnson]

Do you have a borescope?

No. But its not the bore. As the plunger puts pressure on the round/case during extraction, the round/case is contacting a machined edge of the bolt lugs. In other words its happening as I eject the round not as its sliding into the bore. If it really should concern me I can ease the edge of the lug ever so slightly.

 

[nksmfamjp]

Yes, but a borescope will allow good inspection of the chamber walls.
I wonder if it could be cut or honed out somehow.

 

[StumpyJohnson]

Yea it's not in the chamber. It's in the receiver. I pulled the barrel put a clean piece of sized brass into the chamber and pulled it, unmarked.

I placed the same piece into the unbarreled action and pulled it through and watch the score happen.

I was worried it was in the chamber, but it is not.

 

[Roninco]

I have a 6mm Creedmoor that did the same thing. The bolt has dual plunger ejectors canting the case against the side of the receiver during extraction. I removed one of the ejectors to lessen the pressure and issue solved. The small case still ejects just fine.

 

[30BR]

I was going to ask if its a Winchester, because my 22-250 brass gets the same marks.

 

[JuddL]

Yes, I wouldn't like that.

I would pull the ejector spring and cut a round or two off of it…repeat until you don't have the line. If I got to where it wouldn't eject and I still had the line, then I'd reach out to the action manufacturer and see what ideas they had.

If you get to that point, you're going to have to call them to get another spring any way

 

[30BR]

Yes, I wouldn't like that.

I would pull the ejector spring and cut a round or two off of it…repeat until you don't have the line. If I got to where it wouldn't eject and I still had the line, then I'd reach out to the action manufacturer and see what ideas they had.

Done. The ejector pin was a bi***.
But I get a neat pile next to the gun now instead of chasing brass 15 feet away. I live with the lighter marks, and will deal with it next time the barrel comes off.