Green corrosion in 5.56 case necks

[EvilKidsMeal]

I recently purchased about 1,400 pieces of range pick up brass from PSA on Black Friday. A fair amount of brass from one of the boxes has green corrosion, (some looks whitish as well), in the necks of the cases. Some had it on the outside too, but that all tumbled off.

Is there a way to get rid of this?

The first batch has tumbled for about 4-5 hours now and I can tell it cut down on a lot of it. The worst offenders don't appear to be pitted, but I can't feel inside the neck. I am seperating out those cases and plan on taking a bore brush to them to see if it will come off.

If they are not pitted is it safe to fire these even with green left on the surface? I plan on pitching any that don't clean up, but I don't want to have to tumble for days if there is a better way to remove it from non-damaged cases. I don't mind pitching them, but I obviously want as many usable cases as I can get.


EDIT: Forgot to mention I tumble in crushed walnut
Thanks

 

[Sniper 79]

I always say if there is any question pitch it. Although if it is just surface gunk that will come off with a brush it should be ok.

They make case neck brushes. I have a couple from RCBS. As long as they are not pitted or overly corroded they should be ok. Look inside the case with a light also to make sure the inside of the case isn't bad.

Other option is to whack the necks and turn them into 300BLK brass.

 

[EvilKidsMeal]

I am actually going to turn a couple hundred of them into 300BLK cases haha.

Think using a car polish or the Nu-Finish/mineral spirits rumbling method would help any? Would soaking them in vinegar do anything?

 

[Woobie]

You might try a sonic cleaner. If you don't have one and you will meet me in the ECI area, I'll do it for you. It's much more effective on cleaning the inside. It's not particularly effective on corrosion, though. I agree about the case neck brushes, it is tedious, but it is really your best bet.

 

[Mgderf]

Steel rusts, brass oxidizes. Basically the same thing. The whitish substance is likely salts of some type.
It should tumble away, although it may take a while.
Wet tumbling with steel pins may shorten the process.
Minus pitting I would use them.

 

[EvilKidsMeal]

Minus pitting I would use them.

That was my initial thought, but I have only been into reloading for a few months though, so my first thoughts probably aren't correct most of the time haha.

 

[halfmileharry]

Steel rusts, brass oxidizes. Basically the same thing. The whitish substance is likely salts of some type.
It should tumble away, although it may take a while.
Wet tumbling with steel pins may shorten the process.
Minus pitting I would use them.

The green won't hurt. As an old Marine that's polished plenty of brass I'm sure of it.
Tumble the cases and you'll be good to go.

 

[bulletsmith]

I wet tumble mine with the SS pins. Get's the inside of the cases like new. If you are concerned about it I can tumble them for you.

 

[bocefus78]

I bought the same brass you did. I soaked the real bad ones in this:
2 cups hot water
3 drops dish soap
4 tblsp lemon juice

Soak for 2 hours then check. It may take 4 hours total.

It makes the dark really bad ones look decent. Then you can tumble.