A Look At Brass Case Cleaning

BrassCleaningIf you clean your brass as part of the reloading process, you are probably using walnut or corncob in a tumbler or vibratory cleaner. Meanwhile, you have heard about other methods such as stainless media or ultrasonic and are wondering if they could do a better job. The 6.5 Guys have experimented with different cleaning techniques over the years, and we believe our observations will be of interest to those who are reevaluating their current approach.

Intrigued by pictures of cleaned brass looking factory new inside and out, Ed decided to give stainless media a try. True to the pictures, brass comes out looking factory new. This appears to be the best way to clean extremely dirty or corroded brass. There were some drawbacks however:

  • Brass needs to be rinsed and dried taking extra time.
  • The necks of rifle brass get peened creating a bur that needs to be removed. This represents additional processing time if you normally don’t trim every firing.
  • Pistol brass will gall in carbide dies and on expanders. You can get around this by applying a small amount of lube every 10th case or so, but a key reason to use carbide pistol dies is to avoid having to use lube.

Ed ended up going back to walnut media (Steve never left his corn cob). While the outside of a case can come out looking factory new, some carbon remains inside. The remaining carbon does not appear to cause any problems and some have suggested that the trace amounts of carbon in the neck can be beneficial. As far as pistol brass is concerned, we don’t see the galling and sticking that we observed with stainless media.

Walnut and corn cob media can create a lot of dust, but there are a couple of techniques to minimize it:

  • Add a couple of teaspoons of mineral spirits to larger tumblers, and one teaspoon to smaller ones. If you add too much, just let it evaporate.
  • Add a couple of used dryer sheets, paper towels or cloth strips to each batch. Besides controlling dust, they remove dirt that would otherwise stay in the media.

We have not tried ultra-sonic cleaning, but have received some feedback after the video below was created:

  • Like stainless, you need to rinse and dry the cases
  • It removes all of the carbon without peening case necks – a real plus.
  • Unless you have a really large cleaner, you will be limited to the number of cases you can clean. One of Ed’s shooting buddies is actually moving away from ultrasonic to stainless for that very reason.
  • Several cycles might be required if your unit is limited to shorter cycle times. This means you have to babysit it.
  • Some black powder shooters in Norway put together some information on ultrasonic cleaning that we found useful: http://www.svartkrutt.net/articles/vis.php?id=48

For now, the 6.5 Guys are sticking with walnut or corn cob media as there are more benefits than drawbacks. Eventually we’ll give ultrasonic a try as we’re curious to see if pistol brass cleaned using this method will gall carbide dies. We’re curious if the galling is caused by the lack of carbon or the particular texture that stainless media imparts on the brass.

The video below provides additional details and commentary. As always, we welcome feedback from members of our audience.

Update: (January 23, 2015) We’re receiving reports that one can reduce stainless tumbling times significantly by using a mixture of vinegar and water. This would address the peening issues that we’ve observed. We have not tried this yet but welcome any first hand reports from our viewers.

Latest Comments
  1. Phil in AZ

    Hi guys. Phil here (again). Just watched this and would like to pass on some of my tips for wet stainless steel tumbling I have learned. The amount of water used in the drum is important and has an effect on the dinging on case mouths you are experiencing. My Franklin Arsenal tumbler has clear side windows so I can view the process before the water get too dirty. I use a near totally full drum of water and try to only run it once the drum is half to three quarters full of cases. I use double the amount of pins supplied (about 10lbs worth) in large drum. The high water level reduces sloshing and the speed at which the cases and pins move inside. The additional pins clean much better and much quicker so tumbling times are reduced. I usually only tumble for 90 mins now. Using vinegar helps but reduces the detergent cleaning capabilities so you need additional detergent with the vinegar. I have good results with a heaping tablespoon of Lemi-Shine along with a couple ounces of Dawn Ultra strength. To sort cases from pins and drain off the water I use a 14″ baking sifter available from restaurant supply places. It fits over a five gallon bucket and catches all the pins and case and nearly all the water. Lastly, I wouldn’t attempt this process with using the magnet to separate out the pins into a 1 gallon Home Depot paint bucket. Hope this helps some else out.

    • Phil in AZ

      Two additional notes: If you have hard water, use two heaping tablespoons of Lemi-Shine. And, I do not try to get a full “factory new” polish on my cases, I have had many experienced shooters tell me it is a waste of time and money and doesn’t make for a more accurate round. Removing dirt and deposits is all that is needed but the Lemi shine does a good job of getting a nice polish on the cases.

  2. 65guys

    Hi Phil,

    Thanks for providing those tips! Much appreciated.

    Ed and Steve

  3. Bruce Helbert

    I agree pretty much with what you have found. I clean in walnut and use corncob for a nice shinny polish. Treated corncob with Dillon, or even NuFinish works great. SS and a drum work great, but what a mess afterwords. It is a royal PITA to get all the pins out of the brass. What do think would happen if a 30 cal brass pin went bouncing down a 6.5 bore with the bullet? Nothing good, thats for sure. I have a decent size powerful ultrasonic tank I got surplus. It is very powerful, much more so than the little Hornady one. I have found it really does not do a very good job on brass cases. Yes they are clean, but come out just as ugly as they went in. To dry, I pre heat a toaster oven or regular oven and leave the cases on a tray overnite. Works great, but takes time and effort.

  4. Court

    Patrick Sweeney mentioned in one of his books using a chemical cleaner. I use a double dose of Birchwood Casey chemical cleaner in a 5 gallon bucket full of warm water. I dump all my cases in the bucket, stir with a large stick until thoroughly mixed and let sit for an hour. I then dump all cases out on a “bullet catch mesh mat” made for pistols shooters to collect their brass. I then rinse the case with a hose and cut a fan on them for an hour and have sparkling clean brass inside primer pocket and case. It is pretty simple and straight forward after doing it once. I just do it when cleaning large batches of brass. I tumble the brass from then on to remove lube, etc.

  5. Jim in WA

    Guys, just found your site and am really learning a lot about precision rifle. I’m a USPSA handgun competitor, and have had great success cleaning pistol brass with the wet stainless method. I haven’t experienced the galling you mention, but use Hornady One Shot lube on all brass going through my Dillon progressives. I put 100 – 200 rds of previously wet tumbled/dried 9mm or 40 brass in a ziploc and like to tip them all on their sides to avoid getting lube inside the case. Then a light spray is applied onto the brass within the bag and it is rolled/shaked/kneaded for about 30 secs. These get dumped into a an open bin to dry (or the case feeder) and the process is repeated until i have 800 – 1000 for a loading session. This takes about 20 mins. There is no need to remove the lube after loading and it definitely smooths the operation of the progressive loading.

    For the tumbling operation, 1 tsp Lemi-shine and 1 tblsp Dawn dish soap w/ 1 gal tap water into a Thumblers B model cleans very well. I run 2-3 tumblers simultaneously on a timer system that shuts off automatically after selecting 1, 2, or 4 hours. I separate and rinse in one operation by using an older Midway rotary separator which fits on top of a 5 gal pail. I found a cheap plastic dish pan to cover the top of the separator, and made a hole in the center to place my retractable faucet nozzle. I pour the tumbler drum contents into the open separator over a 5 gal pail (all setting in a wash sink), then close everything up and rotate the separator while spraying water down into the closed container. This aids in removing the SS pins from the brass, as well as the residual soap suds. After about a minute of this churning, I open the separator and hose the clean, pin free brass down a little more in the opened separator and shake to drain the remaining water. The brass then gets poured into an old cotton bath towel to further remove excess rinse water. This takes about 10 min with a yield of 500 – 700 rds of pistol brass per tumbler.

    Drying is next done by taking the brass from the towel and placing it into the trays of a modified Harbor Freight food dehydrator. I mod’ed this by removing the heating element in the base and using a small $25 portable space heater and a simple plywood stand which directs the heater air into the bottom of the dehydrator. With the heater on the 1000w setting I can dry 5 trays filled with brass from at least 2 of the tumblers in 1-2 hours. The brass is hot to the touch but not enough to cause burns, about 135-145 deg F. The whole drying system cost less than $75 and quickly removes the residual water which likes to stay in the primer pockets.

    I’ve used this process to clean and load over 30K rounds of pistol brass in the last 2 years. The biggest negative I’ve encountered is a tendency for SS pins to lodge into the primer flash holes of 9mm brass that has been decapped prior to tumbling, breaking primer pins when resizing. I now check for this when lubing, but have abandoned decapping brass prior to wet tumbling. Gotta love that new brass look/ clean primer pockets, but it really doesn’t improve the final product.

    As I do more rifle brass, I’ll be looking for the neck peening mentioned.

    • 65guys

      Thank you for sharing your method with our audience!!!!

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