Brass cleaning, something funny happened

[M1A4ME]

I was sorting a lot of brass yesterday (and have a lot more to sort) and I ran across a small can of 30.06 and .45 acp brass that needed to be cleaned.

I tossed it into one of the vibratory cleaners (crushed walnut shell media), set the timer, turned it on and went into the house for the evening.  When I came out this morning I dumped the brass/media into the separator and then pulled the brass out.  All of it had some kind of light gray crud on it.  The 30.06 cases were way worse than the .45 acp cases.

Anyone ever see anything like this before?  The same cleaner/media was just used the day before for .300 BO brass and it came out nice and shiny after 4 hours.



I then tossed them in the other vibratory cleaner, also crushed walnut shell media, and ran them or almost 3 hrs.  No change in the brass/appearance at all.  Still a light gray color.  Whatever it is will scrape off with my fingernail.  That means tomorrow I'll grab the Lee case trimmer/shell holder stuff, a cordless drill and some 0000 steel wool and do a quick spin/clean/polish on the dirty brass.  I'm just curious as can be about what might have caused this.

I think the brass was fired during a range session last fall when I was in WV.  It wasn't range pickup stuff that had been lying in the dirt/leaves somewhere.  We shot it, we picked it up and I brought it home (no one at home reloads anymore).

Edited to add: 

Forgot to add that I used the same cleaner/media to clean off the .300 BO brass I was making and it all came out nice and shiny just after the ugly brass in the picture.  I wanted to "test" the media in that cleaner but it must be okay since the .300 BO brass didn't have anything built up on it.  Just makes it even odder that the previous batch of brass came out looking the way it did.

[oldfrank]

That is really ugly brass!

I have never seen anything like that. What did the media look like afterwards? Almost like something got added in with the brass.

[Wobbly]

Weird ! Must have been something inside some of the brass.

[rhart]

Ever use Brasso to clean your brass? That stuff can form a coating that will cake up with dirt.

[M1A4ME]

No.  I've read several times that Brasso will harm the brass (Brasso used to have ammonia in it.)  My 40 year old can sitting on the shelf above the washer and dryer is still "stout" with the smell today if I open it up to use in on a light switch cover, door lock, etc. or other brass stuff around the house.

I think maybe I'll clean it up with the Lee hand trimmer shell holder, drill and 0000 steel wool and then run it in the vibratory cleaner again, just to see what happens.  If there's something down in one of the rifle cases it is either gone or it still needs to be removed.

edited to add - the media looked normal.  I used the same cleaner/media an hour or so later to clean up some .300 BO brass I'd been making from .223 cases before I run it through the sizing die and that brass came out nice and shiny.

[ReloaderFred]

Sometimes there's something on the brass that is resistant to the tumbling media, and rather than being polished, it will collect whatever debris there is in the media.  It's kind of like a sponge in that regard.

I use ground corn cob from zoro.com for all my tumbling in all three of my tumblers.  Corn cob absorbs dirt and debris and polishes, while walnut shells are hard and polish by friction and don't absorb.  They both work, but for the individual, it's kind of a Chevy vs. Ford choice.

Try washing your gray brass in a solution of Simple Green or hot water and Dawn dish soap before tumbling it again.  This should remove whatever is on the brass, but make sure the brass is dry before you put it back in the tumbler so media doesn't clump up inside, especially the .30-06 brass.

Hope this helps.

Fred

[srREXed]

Could this be the result of a corrosive ammo sitting for a long time after being fired? Or does the corrosive stuff not leave this residue?

The inside of firearms which I mainly shoot corrosive stuff out of look bad even after a good cleaning and honing with some hand polishing.

I've seen stuff looking much worse than that go into a tumbler and come out like new. Any idea what exactly is the story here? Curious

[M1A4ME]

While I was cleaning/polishing it with the drill/Lee trimmer shell holder and 0000 steel wool I did notice that the brass was HXP 68.  Some we got from the CMP years ago. 

The .300 BO brass I ran through the same media/cleaner but a second time (after it was sized/resized) came out nice and clean again.

Whatever was on the 30.06 and .45 acp brass either isn't in the crushed walnut shell media or isn't being attacted/attached to the .300 BO brass.

The stuff would scrape off with my fingernail, but the walnut shell media just didn't seem to faze it.  Weird.  I know the walnut shell media won't take the really nasty rough corrosion off brass, even after 6 or 8 hour sessions two days in a row.   That's why I've got the little rock polisher/tumbler and stainless steel pins.  That will take off the nasty corrosion in about 4 to 6 hours.

[M1A4ME]

A little more info.

Ran some 30.06 brass yesterday afternoon.  Not for long, about an hour, as I was just getting the resizing lube off it.  Still ran it a bit longer than I usually wood as I was enjoying the warm sun and trimming .300 BO brass at the (relaxing in the sun) bench in front of my garage.

Anyway, this morning I dumped brass and crushed walnut shell media in the separator and took the brass to the relaxing bench to trim and inspect it.

Once again I had some brass with a grayish/white scum on it, but no where near as bad as the batch that run for about 4 hours the other day.

I started separating the brass then by shiny brass vs. scummy brass.

All the shiny brass was a mixture of commercial and USGI (LC, FA, and others - some WW2 brass in there, too).

All the scummy brass was HXP 68.  There was some HXP 72 brass in there but it was clean/shiny.  In case you've not run across it before HXP is Greek surplus from the CMP that was bought when we bought our M1 Garands several years ago.

I didn't think, the other day, to check the headstamps on that batch of scummy brass.  I haven't loaded them yet so they should be an a container at the bench waiting to be primed so I can load them.

I have no idea why the 68 HXP brass had the crud on it and the 72 HXP brass didn't.  I'm assuming the reason there was no trace of the stuff on the other brass was because it didn't run long enough.

Oh, same vibratory cleaner and walnut shell media I'd run two batches of .300 BO brass through in the last couple of days that came out looking good.

[srREXed]

Good to hear. Im interested in the reason why the 68 stuff was bad off.