Which Brass Media Should I Use?
Corn cob, walnut shell and stainless steel pins are the three basic kinds of media used for cleaning and polishing brass cartridges for reloading. Each of these have their advantages and disadvantages. Two important things to consider when choosing a media are; the kind of tumbler you are using and how dirty the brass is.
This is new un-used corn cob media
When to Use Corn Cob Media
If you have once-fired brass or brass that is not heavily tarnished then corn cob media will work to get your brass clean. Corn cob media can be used in both vibratory and rotary tumblers with good success. If you want the brass to come out with a nice bright polish, rather than just clean, you will want to get treated corncob media or add your own polishing compound to untreated corncob media.
This is un-treated black walnut shell media for brass cartridge cleaning.
When to Use Walnut Shell Media
If you have brass that has not been cleaned after many reloads or you have some range pickings that are severely tarnished from sitting on the ground for a long period of time we suggest using crushed walnut shell media. Walnut shell media is a more aggressive media than corncob and for that reason it is best used on heavily tarnished brass casings.
If your are going for a bright polish on your brass it's necessary to get either treated walnut media or add your own polish to untreated walnut shell media. Walnut shell media will work in both rotary and vibratory tumblers. However, we get our best results from walnut media using a Thumler's UV-10 vibratory tumbler.
When to Use Stainless Steel Pins
Stainless steel pin media can only be used in a rotary tumbler such as Thumler's High Speed Model B. This is one of the most effective medias to use for polishing brass in a rotary tumbler. Stainless steel pin media also does a much better job at cleaning the inside of the casing and primer pockets. Using a polish is not required when using stainless steel brass cleaning media as you will be adding a dish detergent or cleaning product.