October 4th, 2007

UltraSonic Update — Brownell's Tests Cleaning Solutions

If you’ve read our feature story on Ultrasonic Cleaning by Jason Baney, you’ve seen the remarkable results that can be achieved with this method. Ultrasonic cleaning has many advantages over traditional tumbling methods of case cleaning. There is no dust or media residue to remove from the brass, and when done right, the cases come out clean and shiney, inside and out, even the primer pockets.

In its Benchtalk Archives, Brownell’s has an excellent article discussing Ultrasonic Case Cleaning. Brownell’s staff compares results, with measured dwell times from 5 to 75 minutes, using both Mpro-7 and HCS 200 cleaning solutions. Tests are performed with once-fired and 5x-fired Tactical 20 cases, as well as once-fired Rem 260 Cases. The article also compares the results from ultrasonic cleaning vs. tumbling in walnut media.

How Does Ultrasonic Cleaning Work?

The Brownell’s article explains: “Ultrasonic cleaning uses high-frequency sound waves (generally between 20-80 kHz) to remove a variety of contaminants from objects immersed in a liquid. The result of these high-frequency sound waves is a process called cavitation. These high frequency bursts of ultrasonic energy produce a three-dimensional wave of alternating positive and negative pressure areas as the sound wave passes through the solution. During negative pressure, microscopic cavitation bubbles form and will continue to grown until they reach resonant size. As the positive sound wave passes, the pressure rises rapidly and implodes these tiny bubbles. Before these miniscule bubbles implode they store a tremendous amount of energy. These bubbles can be as hot as 10,000 degrees and have as much as 50,000 lbs per square inch of pressure. This sounds alarming, but you have to remember that these bubbles are microscopic in nature and pose no harm to anything, unless you are a carbon /powder residue deposit on a cartridge case!

When this cavitation bubble implodes near your brass case, it transforms the bubble into a jet about 1/10th of its size. This jet of energy can travel as fast as 400 km/hour. At 43 kHz, as is the frequency for our L & R HCS 200 ultrasonic cleaner, this is happening 43,000 times per second. This micro-burst of extreme energy is responsible for removing contaminants from the surface of your cartridge brass. Ultrasonic cleaning can reach into crevices and inaccessible areas and remove surface debris that can’t be cleaned by any other process.”

Photos and quotes © 2007, Brownells®, Inc. All Rights Reserved, Used with Permission.

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October 4th, 2007

Big Prizes at St. Thomas GroundHog Shoot

On October 20th, Pennsylvannia’s St. Thomas Sportsman Assn. will host a GroundHog Shoot with major prizes. There will be a drawing for a new Savage .223 Rem model 12 Precision Varminter, and $1000 in cash. The first shooter lucky enough to shoot a perfect 150/150 score will receive $300 in cash and a one ounce gold piece valued at almost $800. That’s $1100 for the first perfect score!

St. Thomas PA GroundHog Shoot

Barry Schmidt reports: “There will be free breakfast, lunch and stuff for all competitors. There will lots of extra drawings for shooting stuff. Non-shooters can sign up and get a chance to be eligible for the drawings. The $1000.00 in cash will be given away in $100 and $50 increments.” For more info, visit the St. Thomas GroundHog Shoot webpage, or click these links for MATCH RULES and DIRECTIONS to the club.

St. Thomas PA GroundHog Shoot

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