I don't know that a standard capacity tumbler would be very helpful in your situation.
Most vibratory tumblers need at least a 50% capacity load, to clean in a reasonable amount of time. The cases scrape the crud off each other as much as, or more than, the media cleans the cases.
I use one of the Berry's-manufactured Cabela's tumblers. For it to work properly with corn cob or walnut media, I have to run at least a 50-75% load. That means 400+ 9mms, 200+ .45s, 300+ .38s, or 150+ .44s. Anything less than that, and it takes ages for the cases to get clean.
The fastest cleaning time in this tumbler is when I have the thing near max capacity.
The cases scrub the crap off each other, and the media carries it away (while doing a minimal amount of 'scrubbing' as well).
So... a smaller tumbler might be more appropriate in your situation. Something like a Thumbler's rotary tumbler or their 10-lb vibratory tumbler come to mind. (The 10-lb tumbler may still be just a bit on the large side, though, for anything but ALL of your brass for one of those cartridges, in each load.)
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