Important tips for filling the barrel with rocks, size, type, quality.
Best Tumbler Barrel Rock Mix.
Rules of the game.
Don't mix really large rocks with really small ones. The big ones will win.
Make sure you have rocks of about the same MOHS hardness. This way the items will tumble in process at the same time. It's like cooking, the sauces take longer to simmer than the peppers.
The barrel has a recommended weight by tumbler. This has to do with the motor capacity of the tumbler. Keep the barrel weight including contents under the max capacity weight.