Through a friend of mine, I got about 5Lb of SS shot of .040 diameter. Looks like tiny spherical pellets, but not like perfect spheres, slightly irregular shape.
IMHO, works just as fine as the cylinders, and none of the pellets stick inside the primer hole. My 9mm mix is about 50% S&B cases - the ones with laquer-painted primers - and even these primer pockets were spotless after tumbling. In comparison, my ultrasonic left most of the laquer intact inside the primer pockets.
My tumbler was a DIY project, but it came out rather nicely:
I put in just under 300 9mm cases - for a total of about 15-20Lb - and tumble for about 3Hrs. I then sort them out by hand, under standing water & inside a large strainer. Just a quick shake makes all the pellets & junk rinse out of those cases. Pellets fall down to the bottom of the strainer, and most of the junk floats.
After a quick roll in a towel I dry my cases over an air vent:
I wish I read the instructions more carefully. I think I dumped too much of Kirkland's dishwasher soap or Lemishine - or both! - and my cases came out discolored, some more so than others:
I'm going to cut back on chemicals, but overall, I'm SOLD! It takes about 45minutes to unload the tumbler, compared to short & frequent trips to the Ultrasonic.