I have seen many reloaders paying highly inflated prices for walnut tumbling media from places like Petsmart, big box sporting goods stores, eBay, and internet sites. Also, shipping costs as much or more than the media if you go mail order. I recommend an internet search. Type in "abrasives" or "blasting media" followed by the city and state you live in. Look for wholesale/industrial suppliers rather than retailers as you avoid another middle man mark up. I did this and found 50 lb bags of walnut media for $16.50 in Tucson and $14 in Phoenix. I'm trying to figure out what is the best grit size to use. Has anyone compared the various sizes to see what cleans best and avoids the problem of clogged primer pockets? Also, what additives are you using?