Brass marks

[michiman]

I’ve noticed some marks on my brass after being fired from my rifle. They are on every single piece in the same exact spot regardless of load or charge weight. They almost look like horizontal scratches just below the shoulder. Any idea what this is from? Does this weaken the brass at all? Or purely cosmetic? How can I fix it?

 

[Supersubes]

Likely happening during feeding or ejection. Next time you shoot it, single feed a few and then carefully eject them and check for marks.

 

[Gee Kay]

Looks like the mark of Zorro ?

 

[LawnMM]

This an auto loaders? If so it's overgassed.

The brass is hitting the ejection port on the way out.

 

[michiman]

This an auto loaders? If so it's overgassed.

The brass is hitting the ejection port on the way out.

it’s a bolt gun, Sako TRG.

 

[918v]

It’s normal. When chambered, the case is always under pressure from the ejector. When you are extracting the case, the ejector is pushing the case to the right. As the case exits the chamber the pressure from the ejector causes it to hit the inside of the action in the area of the bolt lug recess. This causes a slight ding or mark. It is unavoidable.

 

[lash]

It’s normal. When chambered, the case is always under pressure from the ejector. When you are extracting the case, the ejector is pushing the case to the right. As the case exits the chamber the pressure from the ejector causes it to hit the inside of the action in the area of the bolt lug recess. This causes a slight ding or mark. It is unavoidable.

Then I must be living a charmed life as I have 10s of thousands of cases through my bolt guns that did not exhibit that condition. Just maybe it is avoidable.

It does look like it is extraction related though. If it were on my brass, I would be looking at the chamber to make sure that there wasn’t a burr of small piece of brass in there causing that scratch. Actually I’m making the assumption that it is a scratch based on my phone’s limited ability to view those pictures more closely. To me it did not look like a dent as much as a scratch.

I once was experiencing a vertical scratch on my brass in the neck area. After ignoring it for a while, I started by addressing the neck area of the chamber with a good cleaning. After some careful scrubbing, I removed a small brass flake embedded there.

To the OP, is this a new rifle or did this just start happening?

 

[LawnMM]

It's somewhat unavoidable on a plunger ejector, I don't have this but I have a CRF action.

 

[918v]

Then I must be living a charmed life as I have 10s of thousands of cases through my bolt guns that did not exhibit that condition. Just maybe it is avoidable.

It does look like it is extraction related though. If it were on my brass, I would be looking at the chamber to make sure that there wasn’t a burr of small piece of brass in there causing that scratch. Actually I’m making the assumption that it is a scratch based on my phone’s limited ability to view those pictures more closely. To me it did not look like a dent as much as a scratch.

I once was experiencing a vertical scratch on my brass in the neck area. After ignoring it for a while, I started by addressing the neck area of the chamber with a good cleaning. After some careful scrubbing, I removed a small brass flake embedded there.

To the OP, is this a new rifle or did this just start happening?

He has a TRG they all do that.

 

[lash]

He has a TRG they all do that.

Well then, I just learned something. Thanks for clearing that up.