Cleaning Brass For Jackets

As mentioned in the introductory page for this section, it is imperative that the .22LR brass that will form jackets be immaculately clean.  This goes hand-in-hand with quality control (‘QC’) to ensure the best possible, most accurate bullet.

My method of cleaning .22LR brass / jackets is wet tumbling.  I use a Harbor Freight dual drum tumbler, which has served me well so far.  While this tumbler might be too small for most other tumbling tasks (i.e. cleaning a large enough quantity of .223/5.56 brass), the size of each drum is ideal (IMHO) for the batches of .22LR brass that I process.

Wet tumbling involves using stainless steel pins, which when combined with water & citric acid, do a phenomenal job of cleaning brass, including the insides.  Since my use of stainless steel pins is (so far) limited to swaging, I bought a relatively small batch of pins – 2 lbs.  I use 1 pound of pins in each drum.  This smaller quantity of stainless steel pins is available here, among other sources.

My source of citric acid is Lemishine – the product typically used in dishwashers.  There are other sources, including some where bulk quantities of citric acid can be purchased at a lower overall cost.  However, the amount of Lemishine used is very small per batch; I’m perfectly fine paying retail prices for Lemishine at my local store (Target).

The process of tumbling is very simple – combine one Crystal Light container full of .22LR brass (about 575 pieces) and one pound of stainless steel pins in one of the Harbor Freight drums.  I add just enough hot water to cover these items, then I add a squirt of liquid dish detergent.  Then, I add a 9mm case full of Lemishine, and swirl the mixture together for a few moments.  You’ll notice a small amount of outgassing as the tarnished brass & citric acid react.  I don’t seal the drum for a moment or two if only to ensure that pressure doesn’t build up and break the seal, causing a leak.  Once sealed, I tumble this drum for approximately 2 hours (probably longer than necessary, but since this is one part of a batch process and it doesn’t take my hands-on time, its inconsequential.

After two hours have passed, it’s time to separate the pins from the brass.  I use three things to make this easy.  First, a strainer through which the pins can pass but not the .22LR brass. My wife donated a stainless steel strainer that is well suited for this.  Second, a plastic pan larger than the strainer but that will still fit into the sink.  Third, a magnet (the stainless steel pins are magnetic, and some will surely resist separation).

Strainer, pan & magnet

Strainer, pan & magnet

I run hot water through the strainer and into the pan, and begin swirling & hand-mixing the brass to encourage the pins to fall through the strainer.  The pan is catching the pins & the water is helping to rinse the dirty solution away.  I continue to separate the pins this way until I’m sure they’re almost all in the pan and I’ve got ‘clean’ water.  Then, I’ll run the magnet through the strainer picking up any stray pins, or any brass that has been jammed full with several pins.  Tip:  Over-tumbling leads to the pins filling up & sticking inside the brass.  I’ve found that when I tumble for 2 hours or less, this happens infrequently.  If I tumble longer, the odds of getting pins stuck in the brass increases significantly (which is QUITE frustrating).

Once the pins are separated from the brass, the pins go back into the drum for the next batch; I fill the pan with hot water once again and submerge the strainer & brass in the hot water.  I add a pinch of Lemishine to this and ensure it dissolves.  I’ve found that so long as the citric acid solution is the last thing the brass touches before it dries, the brass doesn’t tarnish or water spot.  When just rinsed with water, my hard water will spot the brass.  This has a side benefit of passivating the brass.

The wet brass is laid out on a towel and air-dried with the help of a small fan.  Because the brass isn’t derimmed yet, this may take longer than anticipated, if only because the water hides within the rim.  Once dried, the clean brass is put into a plastic bag along with a sticky note indicating the current state of the brass – “Tumbled” (it’s obvious that it hasn’t been derimmed yet).  I find that using sticky notes is an excellent way to stay organized without permanently marking the container.  Subsequent batches of tumbled & clean brass can be added to the bag as they’re finished, building up a larger supply in one container. Always ensure they’re dry first! Be sure to stop & admire how shiny the brass is at this point…  it will likely look better than new, completely clean and unrecognizable from the tarnished state when you first picked it up off the ground.

This same method of tumbling is also used at several other stages of processing:

  • After derimming (to remove the swaging lube, and to better clean the inside of the brass, which has now been unfolded, revealing additional priming residue).  It’s desirable to remove all of the residue from the inside of the brass; residue can cause the brass to stick on the derimming punch, causing unnecessary aggravation.
  • After annealing (to remove any scaling left behind, and to restore the shine to the now-tarnished brass)

I will also wet tumble the brass one more time – once it’s been point formed into a swaged bullet.  This isn’t a mandatory step, but the final result looks fantastic!

Next – Derimming (Making Jackets)


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