The initial goal was to make a tumbling machine for brass casings without the problematic noise. Mitigating the noisiness was achieved by suspending and isolating a cylinder within a cylinder, the theory being of like sound waves  when they bounce and meet cancel. In this application the theory proven. 

A drum large enough to satisfy a reasonable amount of brass / media also proved to be heavy and unwieldy.  

 So why not separate the outer drum into multiple cylinders? That way you can load different calibers, use different media or separate according to condition or grade of brass. By making them easy to remove ,  they would be easy to handle for filling and emptying and you would not have to remove the entire outer drum. Four 4" cylinders in a 12" drum worked perfectly.

Conventional wisdom dictates baffles, ridges or like obstructions to agitate the contents, right? The brass- media movement was re-evaluated and corrected by em-placing simultaneous lateral motion in conjunction with rotary motion. This way the brass is kept always in contact with the media , with no interference, a subtle modification, but producing highly effective results. 

All Aces.  

  

You can easily Load 250 Rem. 223 casings in one cylinder, 400  9 MM Luger in another cylinder, 150 308 Win. in another cylinder and 350 38 Special in the remaining cylinder. All with different media or any combination that suits you. 

All in the same roll.