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Reloading Basics - Cleaning

Reloading Basics - Cleaning

Depending on how much you use them, reloading dies can soon get dirty and ‘gunked up’ with brass, case lubricant, bullet lubricant and powder residue. Particles of dirt in your resizing die can be crushed and squeezed against the sides of your brass and cause damage. There is also the risk of rust if you reload in a humid location. With regular cleaning and a bit of maintenance, you can prevent the build-up of dirt and contaminants and keep your dies in top condition. The payoff is better and more consistent ammunition, easier and smoother operation of your dies and a longer life for the dies and your cases.

Before you begin

Before you start stripping your dies down for a clean, it is important to remember that you will need to reassemble them and return them to their exact, pre-clean, settings. The best way to do this is to measure as many dimensions on the dies as you can. With your seater die, measure the overall length from the bottom of the die body to the top of the seater stem, plus the distance from the bottom to the underside of the locking ring. With a bullet seater that has a micrometre scale, you can record the setting before you start cleaning and just reset it afterwards.

You should also make a dummy round, with no powder or primer, that you can use to reset your dies after cleaning. It is always worth having one of these around anyway, especially if you experiment with cartridge overall length (COL).

Cleaning equipment

Generally speaking, the equipment you need to clean your dies will be stuff you already have on your reloading bench, so there is no need to buy anything extra. A bore brush wrapped in a patch and soaked in a bore cleaning solvent will take care of the inside surfaces of your dies. Alternatively, you can use a nylon brush, but wire brushes are best avoided, so you do not scratch the polished internal surfaces of your dies. For external surfaces, an old toothbrush or a suede brush will work fine. Just about any bore solvent or degreasing agent will work, but if you shoot a lot of lead bullets, you need to check that it will remove your particular type of bullet lube effectively.

You can use an aggressive commercial degreasing agent, like brake cleaning fluid, and they tend to get the metal surfaces very clean, but not all of them actually dissolve some types of bullet lubricant.

If any of your dies have rubber ‘O’ rings on the locking rings, then be sure to remove them before cleaning, as some solvents can degrade these soft parts easily.

Getting clean

With your dies in pieces, the first thing to do is scrub out the insides in the same way that you clean the bore or chamber of a gun, using patches soaked in solvent over and over until one comes out completely clean. Once the ‘bore’ of each die is clean, it should be left to completely dry while you turn your attention to the other parts.

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The inside of your resizing dies is a particularly important area to keep clean because case lubricant, if left to build up inside the die, can exert hydraulic pressure on your cases and dent them. Dirt can also build up inside resizing dies, particularly if you don’t clean your cases before resizing, and this combines with lubricant to make a ‘slurry’ that can scratch and damage your cases.

If you shoot a lot of lead bullets, then the seater stem from your bullet seating die is likely to be covered in lubricant and this can be removed with a toothbrush soaked in solvent. Alternatively, if the lube deposits are very heavy, then use a plastic scraper.

The neck expander ball on the stem of the depriming pin in your resizing die is likely to have brass deposits on it that are collected from the inside of the case neck during resizing. These can be removed easily with a coarse brush and a wipe over with a cloth soaked in solvent. Do not be tempted to use an abrasive of any sort on this area because its dimensions are critical to case neck tension and bullet seating. If you were to clean the expander ball regularly with even the very finest sandpaper or polishing compound you could reduce the diameter of the ball over time and so affect the inside diameter of the neck of your sized cases.

Crimp dies do not tend to get very dirty because they are used at the end of the reloading cycle and the rounds have already been through several dies, but they are still worth cleaning regularly to keep them performing properly.


Once the cleaned parts have dried out completely, you can reassemble the dies using the measurements you recorded, and the dummy rounds, to set them up as close to their pre-clean setting as possible. They might not go back exactly as you had them, but you should be very close.

Unlike with most other metal components or parts, it’s not a good idea to oil the internal surfaces of reloading dies. Excess oil can contaminate primers or powder charges, build up and attract dirt and cause hydraulics dents in your brass during resizing. The case lube that rubs off inside your resizing die is enough to protect the internal surfaces and bullet seating dies tend to be protected internally by deposits of bullet lube. If you reload in a garage, or anywhere else with a moist atmosphere, it is a good idea to spray the external surfaces of your dies with a light coating of a water-repellent product.


Cleaning dies every 500 rounds will keep them functioning perfectly and ensure they last a lifetime without any problems. Plus, doing this is time well spent because the ammunition that you make will be that bit better and more consistent.


Brunox and Lee Precision – Henry Kranks – www.henrykrank.com
Liqui-Moly – GMK Ltd – www.gmk.co.uk