A few weeks back a friend of mine offered me the use of his ultrasonic cleaner to run some of my cartridge brass through. He assured me that the device was the 8th wonder of the world and would restore the lustre to my long suffering cases and much to my amazement that is exactly what it did. I ran .22 Hornet, .303 Pygmy, .303 British and 6.5X52mm Carcano brass through the gadget and without a word of exaggeration the end result was brass that genuinely looked like it had just left the factory. Some of the cases, like the Hornet brass, had been fired only a small number of times however .303 Pygmy (.303x1.5) had been reloaded dozens of times and tumbled in walnut media only. The end result was the cleanest primer pockets I have seen on fired brass and near spotless interiors.
Ultrasonic cleaners have been around for many years now serving as jeweler cleaners and such and now the mainstream reloading equipment manufacturers have leapt on the bangwagon. Lyman, Hornady and RCBS all offer cleaners operating at high frequency and with heating facility to raise the temperature of the cleaning solutions to optimum operating level. Each company has its own proprietary fluid for the cleaning process but after a small amount of research I was able to establish that favourable results were being achieved by using a solution of white vinegar and water with a small amount of dishwashing liquid. Being a career cheap skate I decided to give this a go and mixed up a litre of 50% white vinegar and water and added a less than scientific '3 or 4 drops' of dishwash.The ultrasonic cleaner I using was not a huge unit and whilst it held 50 .303 British cases I found 40 was a better fit. Of course small cases fit a larger number and 50 of my wildcat .303 Pygmy cases flew into the hopper which holds 500ml of fluid with ease; 600ml at a push. Run time was up to 7 minutes 30 seconds so dropping the first run of brass into the cleaner with the diluted vinegar solution the device was set to run. After the first 7:30 cycle the solution had turned a little murky. By the end of the second cycle the brass was barely visible in the tank. After a third and final cycle the solution was so filthy that visibility was zero. Just remarkable.
.303 Pgymy (.303x1.5) brass prior to treatment in the ultrasonic bath. Most of the cases had been fired many, many times as wildcat and once as the parent case.
The same brass after 3 cycles of 7 minutes and 30 seconds in very warm 50/50 white vinegar and water with a small amount of dishwashing liquid. Pre final rinse was in water with detergent then one final cycle in plain water.
The solution after each of the three cycles of 7 minutes and 30 seconds.
L-R, solution after three cycles, residue in the hopper after rinsing, recovered dried carbon from 45 cases.
Hornet and Carcano brass about to go through the cycle and the finished results.