I got my STM stuff right before then end of 2013.
Settled on using 1/4 tsp. of Lemi-Shine and 3 Tbsp. of Armor-All Wash & Wax in with the water and pins.
Tumbled for 4 hours
Rinsed several times with clean water and set out on a towel overnight to dry.
Brass was as shiny as those in pictures on STM website
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Happened to look at a small bucket of .38 Sp brass I cleaned the first week of 2014.
They have been in this open container in my unheated garage.
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They are still as shiny and bright as the .45 Colts I took out two days ago. Really can't tell the difference between the two batches.
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Just so you know...