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Dry Tumbling Brass 101: Cleaning Cases For Reloading

Cleaning your brass is the first step in any reloading adventure.

You can choose Dry Tumbling or Wet Tumbling.

In this article, we will cover the basics of dry tumbling along with a little comparison of media and other brass cleaning options.

You need to clean your brass so you can get rid of any debris or primer residue so it does not get onto any of your other equipment and mess up your reloaded ammo.

It will make your brass last longer and keep your cases looking good. So buy good brass and still save money.

What Is Dry Tumbling?

A dry tumbler is really just a vibratory bowl cleaner. These are used in lots of different areas not just reloading. One that comes to mind is rock polishing.

The way the dry tumbler works is by having a motor with an offset weight that causes the bowl on top to vibrate. The vibration mixed with the shape of the bowl causes the media and whatever you are cleaning to rotate and cycle around the bowl and up and down.

This basically causes there to be a micro sanding happening the whole time as the cases rub up against each other and whatever media you are using. This is vibratory finishing.

The basic instructions are to fill the tumbler 2/3 of the way with your dry media of choice and then fill the rest with your dirty cases. Turn it on and set your timer to a couple of hours.

Out you will get some nice polished brass. And you can get started on more batches.

Dry tumbling will not clean primer pockets or the inside of the brass very well so if you are concerned about that you can do wet tumbling

Dry Tumbler Media Options

The most popular types of media for dry tumbling are corn cob and walnut shells. Another random option floating around in forums is to use roasted buckwheat.

Corn Cob Media

When you buy corn cob get the right stuff. Do not try to go cheap and get pet bedding or kitty litter that is made out of corn cob. 

Corn cob media that is meant for dry tumbling is only a single part of the corn cob. Just the hard woody part not the chaff or the pith. Then it is separated into different grit sizes or corn cobmesh size so you know exactly what you will get. This is also the same corn cob media that you can buy for sandblasting.

The issue with the cheaper options is that the chaff and pith will get places where you do not want it and will just cause a mess and more work later.

Ground corn cobs should get you a nice shiny high gloss finish.

Walnut Shell Media

This is just crushed up or ground walnut shells. If you can find pet bedding that is walnut shells you should be okay.

Walnut shell media is pretty aggressive and will clean your brass faster than corn cob but it will leave a more satin finish since it scratches more instead of rubbing.

You should be able to find both media types anywhere you can find sandblasting supplies.

Roasted Buckwheat Media

We have not tried this one but found a couple of forum posts about it. Roasted buckwheat is really hard and has a unique shape that helps it rub off residue.

We would also think that since this is not something that has been crushed or cut that it will actually last longer than corn or walnut.

Rice Media

Tumbling brass with rice can be a pretty good media as long as you get a rice kernel that is big enough to not fit in the flash holes.

The good thing about rice is that it is cheap, hard, and absorbent.

The absorbent part makes it stand out a bit from some of the others since it will actually suck up some of the dust and primer residues along with any other waxes that you might be using

Media Additives

These are things that you can add to you chosen media to help it out a bit. It might be to reduce dust, or to help clean, or for polishing.

Cleaning Additives

Lemi Shine or Citric Acid

A popular additive to help clean is Lemi Shine or Citric Acid. This is more frequently used in wet tumbling but it will also help with dry tumbling.

The acid helps to break down residue so the media has an easier time.

Polishing Additives

NuFinish Liquid Car Polish

There are probably other options for liquid finish car polish but Nu Finish is the choice that is the most recommended almost to exclusion.

Just about a 1/8th of a cup of the liquid polish in whatever media you are using and let the tumbler run for 10-15 minutes to let it mix in before putting your brass in.

This will also keep the dust down a bit since the liquid will create a little bit of a sticky compound.

Dust Reduction Additives

Dryer Sheets

A popular choice for dust reduction is used in dryer sheets. We all have more than we need so you might as well get a second use out of them.

Just cut up the dryer sheet into strips and put it in while running. After you are done you will notice that lots of the powder, dust, and primer residue will be stuck to the dryer sheet.

Go ahead and throw the dryer sheets away. This will keep your media clean longer.

Media Separator

You can use the standard gal bucket and strainer or colander method to separate your media and cartridges but, we really prefer to use a real purpose-built media separator. These are built for this purpose and they will save you time.

Our favorite ones are the ones with tops since this provides another layer of protection from dust.

They are basically a tumbling cage in a bucket with slots big enough for the media to go through but not the cartridges.


One of the biggest complaints about dry tumblings is that you are creating lots of unhealthy dust. Just the primer residue alone has lead styphnate which can cause high blood levels of lead.

To help out with dust getting on you or you breathing it in we recommend using some of the tumbling additives that keep the dust down and also using a media separator with a cover.

The last thing to do is to change out your media when you think it is too dirty.

Final Thoughts

If you want to go the dry tumbling way then this is a pretty good run down.

Remember that you should not be mixing your caliber sizes since it is possible that smaller calibers will fit inside of larger calibers.

Thanks for visiting our site. We hope that you found the information that you were looking for here and if you want to check out any of our other reloading guides or articles click some of the links.