Tumbling 8 mm ammo to clean it...

[88comm]

I am looking for opinions- A year or two back I got some 8mm belted ammo from Sportsman or some such dealer at a pretty good price (Romanian?). It came through linked with metal disintegrating links, like for the 1919A4. Ok, I can deal with that. But the ammo and links are pretty well oiled to protect them. So, I can pull the ammo from the links and I like the idea of tumbling them in my reloading tumbler to remove the oil.
Now, if you search the subject on the web, the recommendation is to NOT tumble loaded ammo on the likelihood of breaking up the powder, resulting in increased surface area of the powder and faster burning. Faster burning causes higher chamber pressures.
This is not good news. Probably not a problem with the '42, but I would like to shoot some of it in an older Mauser rifle. I don't want to blow it up.
So, as a test I tumbled a 8mm cartridge for an hour and pulled the bullet, comparing the powder with the same from a cartridge that wasn't tumbled. Laid out in rows beside one another, no difference. Another hour, still no difference. Another hour - if anything the tumbled powder has a slight shine to it, not fine powder, no break up of grains. I have no plans of tumbling anything more than three hours. I see no reason (no difference in powder) for not tumbling to remove outside oil off this ammo.

Anybody have experience one way or the other with this?

Thanks,
Chris

[bolex]

If I read your question right, you are planning to use tumbling to remove oil off the rounds? That is not a good idea because tumbling is an abrasive method to polish the brass and would not be a method to remove oil. I would most likely wipe each round off with a dry cloth. However you could try placing the ammo in some "oil dry" that may absorb the oil from the rounds. "oil dry" is a brand name for an oil aborbant that is sold in auto parts stores to clean up oil on the floor. It is a clay and is similar to cat liter. Some use cat liter to clean up oil spots. It is dusty so you would still may have to wipe the rounds off. I would try several roungs and see if it worked.

[JBaum]

As you have discovered, the old tale that the powder breaks up in a tumbler is an often repeated fantasy. It's as common to hear that as hearing someone say that machine guns are illegal to own. Ignorance repeated from someone else is still ignorance.

Tumble away to clean the rounds, (I think corn cob media be good for this - absorbent, but not dusty,) but don't put any shell polishing additive into the tumbling media. Change as needed, and yell "B.S." anytime you hear the baloney about the powder breaking into little pieces during tumbling and blowing up a gun. I've done it with .45, .308, 8mm, and .50 cal. Works fine for me.

I think the story was made up by someone wanting to sell you clean looking ammo (which they probably tumbled before putting it into the ammo cans they sold it in).

[88comm]

Having hundreds of rounds to clean (maybe hundreds and hundreds of rounds) the idea of wiping each one by hand is not an attractive option. The oil itself is a little interesting, as it does not run off the ammo and pool in the bottom of the can. I would compare it to what is called "way oil," an oil that is formulated to stick and not run. It is used on metal working machines to lubricate and protect machined surfaces from moisture and wear. In short - this stuff won't wipe off easily. A spray solvent might penetrate into the case, ruining the powder.

Bolex - the cat litter or oil dry may work well in the tumbler. I might expect it to turn to dust after a while, but it might work well. A little sawdust in the mix might help as well.
Hand wiping is not a realistic option in my mind.

Jbaum, Your experience reinforces mine. Any particular reason to not polish as I remove the oil? The oil seems to be enough to be a nusance, but not enough to make any media wet or oily. Clean, shiny brass would seem to be easier to check for irregularities, cracked necks, etc.

thanks,
chris

[JBaum]

I just thought that the polishing compound in the media would reduce the media's ability to absorb oil. If you don't have anything else to do and want the rounds to look pretty, go ahead.

[bolex]

Try a few rounds in the tumbler and report back how it works. I wonder if the "way oil" will make the corn cob pieces stick together. The quick way to find out is to try it.

Oh btw I was thinking more of just placing the rounds in a bucket with "oil dry" and letting them stay for a few minutes/hours.

[88comm]

The media I am using looks a lot like the clay kitty litter, but it does not break like clay. It had a red (polishing rouge) color, and has yet to really get what you would call wet. It doesn't even look damp. If anything the oil is keeping down the dust.

I think putting the ammo in a bucket with oil dry for an extended period might work. I would be tempted to put the bucket in a hot attic to help the transfer of oil. How extended a period? Maybe a wekk or two...

Currently with my tests I have clean ammo and little difference in my media.