I am amazed at the Thumblers Tumbler and stainless pins I am now using, they clean brass like nothing I have ever tried before.
I got my tumbler about two weeks ago from STM and have since tumbled rifle and handgun brass and I can tell you that no amount of tumbling in a vibrating tumbler with any kind of media I have ever used comes even close to the stainless steel pins. With my old tumbler the outside of the case looked petty good but the inside of the case and the primer pocket were never clean.
I just got done tumbling some .45 ACP cases that I had all ready tumbled in my old RCBS vibrating tumbler and that looked OK and now they look brand new. What a difference!
Ken