Not to beat a dead horse, but yesterday I went down to a local gun shop that has a number of Thumler's Tumblers in the display case. I asked the guy behind the counter, "why do I want my fired brass shiny and clean on the inside?". He said, "because your fired brass will be like new." I reminded him that it might look new but it does not make it new. He took me in back and introduced me to his gunsmith. This guy has been a gunsmith since back when Jesus wore knickers. He related to me that smokeless powder residue comes off in flakes after repeated firings and a thought or theory suggests these flakes cause increased throat and barrel erosion. He showed me an article from Brownells and nowhere does it mention this has actually been scientifically proven. The gunsmith said that he actually does tumble with stainless pins, water, and Dawn detergent all of his .223 brass for his AR's, only because he fires 100s of rounds on an outing. Like CC said, he told me I should have no concern with my big game rifles because I'm not firing hundreds of rounds through them at the range. Clean them every 10 -12 rounds and no worries.