Some dude devised this simple modification of an ammo tray with small round nubs in each cavity, larger than a small primer (.177) but smaller than a large primer (.223). The idea is that large primer pocket brass will fit over the nubs and sit lower in the tray, while small primer pocket brass will sit atop the nubs and expose itself higher in the tray.
And in this way, you can just scoop large quantities of brass and let the heavier bases cause them to mostly come to rest case mouth upward, allowing you to rapidly fish out the different pieces from each other.
The principle works the same for other calibers with the same problem, like 10mm and 7.62x39. In fact, both of those calibers are similar enough in base diameter, a tray for either would work for both.
I saved the images, but then closed my browser and forgot where the heck I saw them in the first place,...so I can't provide a link. (It was at some Etsy-ish type of cottage home business marketing website.) But it wouldn't be too hard, if you have a 3D printer to design this and make a few yourself.
