How to clean your rifle brass - a guide for reloaders

When you’re reloading rifle brass, clean cases are the foundation of safe, accurate and consistent ammunition. You can’t get away from cleaning your cases. Dirty brass will abrade your sizing dies, make case defects harder for you to spot, and can affect primer ignition and chamber pressures. Cleaning your brass regularly and properly can extend the life of both your brass and your dies, and it can keep every reload performing the way you expect.

You can approach cleaning brass in two different ways - dry tumbling and wet tumbling. Both work, and both have strengths, but they have different purposes. In this guide, we’re going to walk you through both methods in full - how to choose the right equipment and media for how you reload, whether you’re running a few hundred cases a week or prepping for a precision long-range match.

Why do you need to clean rifle brass?

Some reloaders skip cleaning - particularly when working with newer brass that hasn’t been through many firing cycles. There are very good reasons to make cleaning a standard part of your brass prep:

Dirty brass damages sizing dies

Carbon, dirt and grit act as abrasives. Running uncleaned cases through expensive dies shortens their lifespan and can score the die surface.

Residue inside the case can affect consistency

Carbon and primer residue inside the case body and primer pocket can make ignition less reliable and make powder charge measurements less repeatable.

Clean brass is easier to inspect

Cracks, case head separation, dents and neck splits are much easier to spot on clean cases. Running damaged brass is dangerous - cleaning gives you the ability to catch problems before they become failures.

Polished brass feeds more reliably

Especially in semi-automatic platforms, clean, smooth brass chambers and extracts more reliably than dirty cases.

Method 1 - dry tumbling (the most popular approach)

Dry tumbling is by far the most popular method for cleaning brass. Cases go into a vibratory tumbler along with a dry abrasive media (usually corn cob or walnut shell) and the tumbling action scrubs carbon, dirt and oxidation from the outside of the case, leaving it clean and polished.

It’s simple, effective, and it’s easy to run while you’re doing something else. For most rifle reloaders cleaning moderately dirty brass, dry tumbling in a vibratory tumbler type brass system is probably all you will ever need.

Choosing your dry media

The two most common dry media options are corn cob or walnut shell, and they work differently:

• Corn cob media is finer and lighter. It produces a brighter, more polished finish and is the right choice when your brass is reasonably clean and you want it to shine. Corn cob is also gentler on the brass surface.

•  Walnut shell media is coarser and more aggressive. It cuts through heavier tarnish, carbon fouling, and surface corrosion more effectively than corn cob. If your brass is heavily dirty or has been sitting for a while, start with walnut.

Treated media (adding a small amount of brass polish to your media) boosts the shine on corn cob in particular, helping to produce a near-mirror finish on clean brass.

You should also deprime your brass before tumbling. This lets the media get into the primer pocket and flash hole, removing spent primer residue along with exterior dirt. It also lets you inspect primer pockets after cleaning.

Step by step - dry tumbling rifle brass

• Deprime your cases first if possible.
• Fill your vibratory tumbler with dry media - roughly 2 parts media to 1 part brass by volume.
• Add your brass cases. Avoid overfilling; the media and cases need room to move.
• Close the lid and run the tumbler. For lightly dirty brass, 1-2 hours is usually enough. For dirtier or tarnished cases, run 3-6 hours. Check periodically.
• Once done, pour the brass and media through a media separator to divide the cases from the media.
• Inspect every case. Check that no media is lodged in flash holes or inside case necks - this is a common issue, especially with corn cob in larger calibers.
• Your brass is now clean, polished, and ready for sizing.

Method 2 - wet tumbling (the more advanced choice)

Wet tumbling takes brass cleaning to a different level. Instead of dry media, you use a rotary tumbler with water, a cleaning solution, and tumbling media - either stainless steel pins or ceramic rods and spheres. The media gets inside the case, into primer pockets, and into flash holes, cleaning thoroughly from the inside out.

The result is brass that is cleaner in every measurable sense than anything dry tumbling can achieve. For precision long-range reloading - where consistency in primer pocket depth, case neck tension, and internal cleanliness makes a difference - wet tumbling is worth the extra step.

What to use as a cleaning solution

The cleaning solution you add to the wet tumble matters. A small amount of dish soap will technically work in a pinch, but it's not formulated for brass and doesn't address oxidation or carbon the same way a purpose-built solution does.

We have our own brass care cleaning solution specifically designed for this. It's non-acidic, which means it won't leach copper from your brass or cause the surface degradation that acid-based cleaners can cause over repeated use. It attacks carbon, dirt, and oils directly, and it's concentrated - a single bottle makes up to 21 gallons of cleaning solution. It also includes a built-in metering cup so your cleaning strength is consistent batch after batch.

Step by step - how to wet tumble brass

• Deprime your brass before wet tumbling. This is especially important because it allows thorough cleaning of primer pockets and lets you verify pocket cleanliness after the process.
•  Load your rotary tumbler drum with brass cases.
• Add your media.
• Fill with water to the manufacturer's recommended level.
• Add a measured amount of brass cleaning solution using the built-in metering cup. Follow the dilution ratio on the bottle.
• Seal the drum and run the tumbler for 1.5 to 3 hours.
• Drain the drum. Separate media from brass using a pin separator or sieve.
• Rinse your cases thoroughly with clean water - ideally hot, which speeds drying.
• Dry completely before processing further. Use a food dehydrator set to a low temperature, an oven on the lowest setting with the door cracked or spread cases in the sun on a warm day. Do not attempt to size, prime, or load wet brass.

How to clean heavily corroded or tarnished brass

Heavily corroded brass - particularly range brass that's spent time outdoors - needs a different approach. Before you invest time cleaning it, start with a visual inspection: cracks, splits, deep pitting at the case head, or visible case head separation all mean you should throw the case away, regardless of how clean you can get it. Surface corrosion alone doesn't make brass unsafe; structural damage does.

For cases with heavy surface tarnish or corrosion, wet tumbling consistently outperforms dry tumbling. The Creedmoor Brass Care Cleaning Solution is particularly effective here - a pre-soak in the solution before tumbling breaks down heavy oxidation and fouling, dramatically reducing how long you need to run the tumbler.

If you're dry tumbling heavily corroded brass, use walnut media rather than corn cob, run a longer cycle (4 to 6 hours), and consider extending the cycle further if needed. Walnut's more aggressive cut is much better suited to this kind of cleanup work.

After cleaning heavily corroded brass, always inspect neck wall thickness and check for any work hardening. If your cases have been fired five or more times, annealing after cleaning is good practice to restore neck and shoulder ductility.

One common question we get is whether you should use WD-40 for cleaning brass. The answer is a definite no - WD-40 shouldn’t be used to clean brass. WD-40 is a water displacer and short-term lubricant, not a brass cleaner. Any residue left inside a case can contaminate your powder charge. Stick to purpose-built cleaning solutions.

Which method of cleaning brass is right for you?

The honest answer is: it depends on how you reload and what you're loading for.

Dry tumbling in a vibratory tumbler is the right starting point for most reloaders. It's simple, effective, and handles most cleaning tasks well. If you're loading hunting ammunition, plinking rounds, or service rifle ammunition where absolute primer pocket cleanliness isn't a priority, a good vibratory tumbler with the right media will serve you well.

Wet tumbling is the better choice for precision reloading. If you're loading for long-range competition, benchrest, or any application where consistency matters round to round, wet tumbling - particularly with Creedmoor Sports Brass Care cleaning solution - gives you a level of cleanliness that dry tumbling can't match. Clean primer pockets mean more consistent primer seating depth. Clean case interiors mean more consistent powder charges and ignition.

Many serious reloaders use both: wet tumbling once-fired brass the first time it comes through, then dry tumbling for subsequent cleaning cycles when the cases are already reasonably clean. This keeps the process fast without sacrificing the initial deep clean.

Frequently Asked Questions (FAQs) about rifle brass cleaning

Should you clean rifle brass?

Yes. Cleaning rifle brass extends the life of your sizing dies, makes case inspection easier and more reliable, and ensures consistent primer pocket depth and case interior conditions. It's an essential step in safe, accurate reloading.

What media is best for cleaning rifle brass?

For dry tumbling, corn cob media gives a brighter polish on moderately dirty brass, while walnut shell provides a more aggressive clean for tarnished or heavily fouled cases.

Is Dawn dish soap safe for brass?

A small amount of dish soap in a wet tumble will clean brass without damaging it. That said, it isn't formulated to remove oxidation or break down carbon the way a purpose-built solution does. A dedicated brass cleaning solution is a better choice.

Is WD-40 good for cleaning brass?

No. WD-40 is a water displacer and light lubricant, not a cleaner. It will not remove carbon, primer residue, or oxidation effectively, and any residue left inside a case can contaminate your powder charge. Use a dedicated brass cleaning solution.

How do you clean the inside of brass cases?

Dry tumbling primarily cleans the exterior of brass cases. To clean the inside of the case - including primer pockets and flash holes - wet tumbling is the most effective method.