Rock River Arms AR-15 - Shaving brass from the casings

Hey everyone.

I just built a RRA AR 15. I went out and bought a stripped lower. I then went online to RRA's website and ordered everything I need to build the rifle. I got one package with all the parts to do the lower, but nothing else. So I had a completed lower which was nothing more then a paper weight.

I got anxious and bought a completed upper in a store. So I slapped the completed upper on the lower I built and now I have a complete AR-15.

I went to the shooting range and she performs like a dream from the first shot. I put about 200rds through her in the first go around without a hiccup.

But... When I came home to clean the rifle I noticed lots of little tiny brass shavings in my upper receiver. They are about the size of the period at the end of this sentence. Some maybe a little bigger. I know this isnt good.

So I got out my Sharpie marker and marked up 10 rounds and shot them to see where the casing is getting scratched.

It turns out the scratches are on the neck of the casing. 2 of them, about 1/4inch apart. Looks like: ' '. It is on the side facing the ejection port.

I tried taking pics but they didn't come out right. I will try again when I can find a better camera.

Let me know if you have any ideas about what it could be.

Thanks.

I think this is due to an issue in the barrel chamber area.

Inspect the chamber area and clean it with a stainless steel bore brush and see if that gets rid of the high spot that may be there. A visual inspection first before you start ;)

If that fails then I would consider a return of the upper to the place where you got it from for a replacement.


good luck

If you look at the chamber end of the barrel you can see a left and right feed ramp. The marks on your cases may be caused by sharp edges on the ramps. You can remove as much as you want the “soften” these edges.
Steve

I pick up a lot of range brass and see this occasionally. I dont know the cause but it cant be too big an issue.


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