Marks on brass at case head

[SS 396]

Hey Ingoers. can anyone tell me what causes these marks at the case head. These have all been shot from a 1911. I have a lot of brass giving to me buy a good friend who shot 1911s, most all the brass has these marks. The 9mm brass has come from my 1911 i am thinking maybe the ejector is leaving the marks, the extractor is not going over the case it is slipping under as it should. As you can see i have loaded the 9mm several times already, and the marks are all over. It does not seem to hurt function just curious to the cause. Seems to be only 1911s causing these marks.








sorry the pictures would have been better i did not get my lighting out.

 

[Cam]

Inside edge of the extractor is my guess.

 

[Drail]

Look closely at your breechface and you will see a mirror image of those marks. It is poor machining caused by two different cutters that are not set to cut at the same depth. The dent is caused by a small step left on the side of the breechface opposite the extractor. It can be fixed with a machinist scraper and a file or a small stone. I had two Springfield Mil specs that did this and I cleaned them up and stopped it. If you don't reload your own ammo I would forget about it. It will shorten the life of the cases if they are reused over and over. Eventually the rim will become peened over enough that the cases will have trouble sliding under the extractor hook and will force it past its correct setting or the case may not seat fully in the chamber. This is pretty common on mass produced guns. If the gun is under warranty make them fix it. You will only need to ship the slide instead of the whole gun. Love your Chevelle.

 

[BE Mike]

Look closely at your breechface and you will see a mirror image of those marks. It is poor machining caused by two different cutters that are not set to cut at the same depth. The dent is caused by a small step left on the side of the breechface opposite the extractor. It can be fixed with a machinist scraper and a file or a small stone. I had two Springfield Mil specs that did this and I cleaned them up and stopped it. If you don't reload your own ammo I would forget about it. It will shorten the life of the cases if they are reused over and over. Eventually the rim will become peened over enough that the cases will have trouble sliding under the extractor hook and will force it past its correct setting or the case may not seat fully in the chamber. This is pretty common on mass produced guns. If the gun is under warranty make them fix it. You will only need to ship the slide instead of the whole gun. Love your Chevelle.

Drail hit the nail...sorry, I couldn't help it. I just noticed the same thing on the brass of my SA 1911. Apparently a few of these slides slipped by QC. Like Drail said, I cleaned up the unmachined "step" on my breech face (opposite side from the extractor). I was told that leaving it there, in addition to bending the rim, would also cause the round to be chambered at a slight angle and would affect accuracy. If you don't have the tools or patience to do it, contact SA. I'm sure that they will fix the problem for you.

 

[SS 396]

Thank You very much Drail and BE Mike, checked my breechface and sure enough a slight ledge by the J cut. Dressed it down with a stone and polished the breech face took it out for a function check no more marks on my brass I do reload and hated to see my cases damaged. Thanks again guys, checked my other 6 1911s they were good to go was just my 9mm 1911.

 

[tnek13]

Ditto on extractor.

 

[Leo]

Glad you go it worked out.

 

[noylj]

They're not damaged, just marked.
Reload and be happy.

 

[BE Mike]

They're not damaged, just marked.
Reload and be happy.

Actually my extracted cases, while usable, had the rim bent inwards, somewhat.