I've got one of these:
Jewelry Polishing Tools 5kg Capacity Rotary Tumbler Rock Tumbler Polishing Machine Jewelry-in Jewelry Tools & Equipments from Jewelry on Aliexpress.com | Alibaba Group
With 9mm I'll tumble for 1 hour with @150 in the container, fill with water to cover, drop of dish washing liquid and a sprinkle of citric acid powder. Same time for 223 but I do less in one run, prob @60 at a time.
Bookmarks