Cleaning Reloading Dies with an Ultrasonic Cleaner

Disgusting. That’s the word I use to describe my crusty jar of mineral spirits that I use to clean dies. It’s a mess to use, and when I blow dry the dies there’s a fine mist of mineral spirits that you can smell in the shop air. You may know the feeling: the excitement of unboxing dies, and the realization that you’ll need to spend 15-20 minutes cleaning them until they are “de-gunked” of the factory oil and ready to use in your press. I’ll admit, I’ve used dies without cleaning them, and while it may not cause many problems, at minimum they can coat your fingers with oil each time you touch them. It’s not satisfying to use dies that have gummed up factory oil on them: I don’t even like the look of oiled-up dies on my presses. For me, it’s time to turn the page- I’m hoping I’ve found a better way to keep my dies clean. We’ll see!


After getting a new RCBS ultrasonic cleaner, I thought I should give that a try instead of my old crusty jar. RCBS has both “Weapons Cleaning Solution” (intended for guns and gun parts) and “Case Cleaning Solution” (intended for brass). Since reloading dies are pretty much like gun parts, I thought I would give the Weapons Cleaning Solution a try. The RCBS Weapons Cleaning Solution comes in a 32 fluid oz. container that has a handy built-in measuring/dispensing chamber. The instructions state that you should use a minimum of 40 parts water to 1 part cleaning solution, up to a maximum of 14 parts water to 1 part cleaning solution. I chose a middle value of 30 parts water to 1 part solution when I mixed the batch used for this article and video.

RCBS Weapons Cleaner

Here’s the video, which shows the setup, cleaning cycle, and drying procedure that I used to clean some brand new RCBS 45 ACP dies:

Here’s how the parts came out of the cleaner (after some drying time):

RCBS Dies Drying

After the parts were completely dry, they felt clean, and according to RCBS they now have a protective film of corrosion protection. Thankfully, this film of protection is not something that’s apparent when you handle the parts. That would defeat the purpose of cleaning new dies wouldn’t it?

I think I’ll go and clean my first batch of brass with this Ultrasonic Cleaner!

Talk to you all soon,

13 thoughts on “Cleaning Reloading Dies with an Ultrasonic Cleaner”

  1. Looks like you had better results than I did a few years ago. I thought I’d try cleaning my Redding Type ‘S’ F/L bushing die in my ulrasonic cleaner… it came out with some weird black marks on the surfaces nearest the transducers, almost looked like it ‘burned’ the exterior ‘finish’ of the die. Haven’t tried it since, but it is entirely possible that it may have been due to a chemical interaction – I was using Citranox, a common US cleaning agent at the time.

  2. Factory oil IS messy but the real problem would be the metal particles, shavings, thread curly cues & nicks, etc., that can cause bigger problems if not cleaned up.
    I always clean dies once, chase the threads inside and out, and finally clean them thoroughly before I use them. Less likely with some die makers but I have found one or two by all makers that needed to be chased and cleaned.
    A full length sizing die with a scored inner surface due to shavings being forced into it can ruin the die forever.
    I may be guilty of overdoing it on occasion but I have the luxury of time and learned patience from past mistakes.

  3. I run 4 Dillon Super 1050s, which fully process a combined total of over 10,000 .223 Remington and .308 Winchester every day. I use Dillon carbide dies, and my own lube that’s lanolin-based.
    In a good month, I’ll process over 200,000 cases.
    I’ve never cleaned my sizing dies. Ever. Not when they were new, not after millions of cases.
    I also don’t own an ultrasonic cleaner, and likely never will. I use Diamond Pacific 65T tumblers, specially sized stainless steel pins, Dawn and Lemishine. It’s an unbeatable combination that provides fantastic results with zero problems.

  4. A suggestion:
    Try putting the parts for each die into a sandwich size baggie with enough cleaning fluid to completely cover the parts when you set it on a flat surface. Place the baggies in the sonic cleaner’s tub. Then fill the tub with water and run.

    This makes clean up incredibly easy – remove the baggies and dump the clean water from the tub. The baggies contain the mess!

    This is the best way I’ve found when cleaning particularly dirty gun parts and brass!

  5. This question will probably raise some hackles, concerns and derision but I’d like to find a cheap alternative for tool and gun parts cleaning. I used to use trisodium phosphate for all kinds of cleaning projects. It seem like it would be ideal for tools, dies, gun parts. I know it is bad for aluminum and chrome. So lets hear the pros and cons for trisodium phosphate use in the shop or in a ultrasonic cleaner?

  6. Simple Green works exceptionally well on everything oily…dirty…grimy…cheap and it works. Simple Green offends some people as far as smell goes though there has only been a scant few that the smell of Simple Green has bothered in my home remodeling/gun working. Sometimes you do need a tooth brush to help the process along and that is why I use a cordless electric tooth brush which makes quick work of cleaning oily parts. You can also let the parts soak for a bit before brushing….just dry with a hair dryer and oil after drying.

    TSP….it etches surfaces and yes…it cleans alright….but seeing the effects TSP has on too many surfaces….I wouldn’t use TSP for gun parts/etc but then again…it’s not my guns and/or accessories.

    I have not forked out the money yet for a sonic cleaner but I should buy one for brass cleaning/etc….cleaning dies? I cannot think of a reason why you wouldn’t use a sonic cleaner for this….just need to cough up the bucks for one….Been reading up on the Lyman sonic cleaners.

    Has anyone used a sonic cleaner for pistol dies with a lube buildup on the seating and/or crimping die? I have to be cleaned mine occasionally because of the buildup of Alox lube from lead bullets. I have to take apart…use Q Tips to removed the lube buildup using solvent since even Simple Green has a hard time emulsifying that Alox lube.

    1. Add on…I have to use a nylon bore brush to get into the pistol die interior and remove any leftover lube.

  7. Would love to try my new RCBS sonic cleaner on some dies and/or gun parts but can’t find the “Weapons cleaning solution”…. just the brass cleaner. Any suggestions?

    1. I ordered both my RCBS case cleaning solution and the weapons cleaning solution from Brownells when I ordered the sonic cleaner itself. They have both.

      1. I’ve had the pleasure of owning the Rcbs sonic cleaner, and have cleaned over 600 brass which come out perfect. If you want the inside spotless run them through again let em soak a bit longer and a q tip push around the primer pocket will make em like new.
        It’s much safer to run these cases into your dies so not the scratch the die from left over media etc.
        Also the ultra sonic on gun parts and dies have work exceptionally well…removes all waxes and build up well we all know the issues dirty dies can cause.
        Anyhow anyone looking to get one I advise them to just make sure the interior is large enough to fit your gun parts and you won’t regret it.

        I’ve must also say to those that reload for accuracy and want the most consistent annealing process the sonic cleaning will clean the brass so well that your annealer can evenly hear brass necks much better as well. Even neck tension….I’m in!
        Thanks for reading hope it helped some !

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