Does copper oxide weaken brass?

[DrDoom]

Hello everyone, I'm new to this forum. I was prepping some 9mm brass. After cleaning and polishing, I noticed a lot of the cases had green copper oxide(or carbonate not sure) inside. Does this weaken the case at all? I'm loading 5.8grs of Bluedot behind a 147gr jacketed flat point. This is ammo intended to be shot from an Uzi. Thanks.

 

[dcali]

If it’s just a light surface corrosion, it’s probably fine. If the case is getting pitted, I’d chuck it.

 

[ronemus]

Copper oxide is black - green is most likely copper chloride.

 

[DrDoom]

If it’s just a light surface corrosion, it’s probably fine. If the case is getting pitted, I’d chuck it.

It seems to be surface only and it's on the inside of the case only. The exteriors on a lot of the case are tarnished but there doesn't seem to be any pitting.

 

[David101]

Short answer is yes. However you should be able to see how bad being on the inside is going to make things harder in that regard. The powder must be contributing to the problem.

 

[ronemus]

The cases may be from corrosive ammunition - to be safe, rinse well in hot water before reloading.

Chlorides will react with stainless and will start corrosion on carbon steel, so it isn't something you want to introduce into your bore(s).

 

[Texas10]

You mention polishing the brass, if you're using a polish that contains ammonia like many of the brass polishes do, you may have to scrap the brass. It will chemically harden the brass, in addition to causing pitting. Bad combination.

https://au.answers.yahoo.com/questi...0403212321AAvwKCY&p=ammonia harms rifle brass

 

[jonbearman]

Do you know anyone with a stainless steel pin tumbler? Were they ground pick ups or something you want to reload that was once fired by you?

 

[Texas10]

Get a cheap tumbler from Harbor Freight Tools, and some media from Sleeping Giant Brass. Warm water, dish soap and a little Lemi-Shine will fix you right up.

 

[DrDoom]

I am using polish I purchased from Midway so I assume that shouldn't be a problem. All the brass is commercial, mostly Winchester with some Federal, PMC and Remington mixed in.

 

[Webster]

You mention polishing the brass, if you're using a polish that contains ammonia like many of the brass polishes do, you may have to scrap the brass. It will chemically harden the brass, in addition to causing pitting. Bad combination.

https://au.answers.yahoo.com/question/index;_ylt=A0geJaPg0pZcIS0A1IdXNyoA;_ylu=X3oDMTEyMDNmZmswBGNvbG8DYmYxBHBvcwMzBHZ0aWQDQjY4MjFfMQRzZWMDc3I-?qid=20080403212321AAvwKCY&p=ammonia harms rifle brass

Ammonia does not harden brass, but is the worst chemical to expose brass to. It quickly initiates stress corrosion cracking.

 

[stifffingers]

I am using polish I purchased from Midway so I assume that shouldn't be a problem. All the brass is commercial, mostly Winchester with some Federal, PMC and Remington mixed in.

You admit your a novice and shooting an Uzi. Any brass or brand will work just fine. However if you intend to improve and maybe buy a target rifle you would shoot quality brass all with the same head stamp. That's just the beginning. It's a deep well your falling into. If you truly want the best advice available you might want to buy Tony Boyers book of Rifle Accuracy. It is meant for all shooters that want to load and improve. Splains every thing, from the most acclaimed precision shooter ever. So sorry, just re read your first post, your new to this forum maybe not to the shooting sports.

 

[DrDoom]

Update It seems that the green copper salt whether it's copper carbonate or chloride mostly appears after the brass has been sized. It flakes off the inside of the case. I'm seeing this with Winchester, Federal, and Remington brass. I have some PMC brass mixed in that has no green copper salt at all. I must have 10,000 9mm cases like this so concerned if this is a problem.