*Updated* Marks on Casing..??

[SSOUNN]

[hermosabeach]

I would stop

A new rifle should not make those marks

[hermosabeach]

I would stop

A new rifle should not make those marks

Pull the bolt

Run a q-tip into the bore

Do you find a burr?

Cover a round with sharpie- all black

Sharpie will scratch off easily

Load a round into a mag and push out by hand. Same marks?

Re coat with sharpie- load round into mag. Slowly release bolt and load 1/4 of the cartridge. Then eject the round.

Do you see the marks yet?

Blah blah blah
Safe direction for ND
Eyes and ears
Use dummy rounds not live Ammo

[SSOUNN]

Ran a cotton swab, shine a light and looked inside chamber, nothing

[toiletfighter]

Metal mags? Maybe the round is rubbing the feed lips?

Just a wild guess I pulled out of my ***.

[baih777]

Feel the inside of the mag lips to see if there is a burr.

[kcheung2]

I agree that it's the magazine lips.

[FeuerFrei]

Ran a cotton swab, shine a light and looked inside chamber, nothing

Ignore the marks. That's what slow hand cycling the action will do to brass.

Go shoot it. If those marks get worse then you may have some burrs to take down.

You'll be amazed how this little crap disappears when the action is cycling at normal speed.

[SSOUNN]

Metal mags? Maybe the round is rubbing the feed lips?

Just a wild guess I pulled out of my ***.

Gen 3 10/20rd Pmag

[SanDiego619]

Can you feel the scratches with your finger or are they just light surface rubs?

I would shoot it.

[SSOUNN]

Can you feel the scratches with your finger or are they just light surface rubs?

I would shoot it.

Light surface rubs

[CoopsDad]

I had a DPMS that put marks similar to those on the cases, both handle cycled or fired. I never found any defects in the chamber and it did it with the factory metal mags and P-mags. I put a lot of rounds downrange with that gun and it never changed. I figured it was rubbing on something as the cartridge fed from the mag into the chamber because it didn't show up if I fed a single round directly into the chamber and let the bolt slam home.

[SanDiego619]

Light surface rubs

I wouldn't worry about it. See how it shoots.

I don't know what you built but I have a PSA "AR-10" they call the PA-10 and I love it. I put a Thordsen stock, bipod, and big scope on it. It is kind of funny looking but it shoots great.

[SSOUNN]

I wouldn't worry about it. See how it shoots.

I don't know what you built but I have a PSA "AR-10" they call the PA-10 and I love it. I put a Thordsen stock, bipod, and big scope on it. It is kind of funny looking but it shoots great.

[Bullets&Whitewalls]

I would shoot it myself. I have noticed that hand cycling vs. normal fired cycling always leaves different marks on the brass. Truthfully, I would be more concerned had there been no marks at all after hand cycling. Brass is soft it will get marks on it when rubbing against steel. Enjoy the rifle it looks nice. I know you said it was a PMag but in the pic it has a metal one. they could have happened before, and you didn't notice?? They do look like mag marks to me.