Just a "I tried this" post. I looked for black airsoft BBs but in my small town there were only white, red, and dayglow green. I wanted black! I remembered some time back moly coating was popular and regular copper coated steel BBs were used to tumble with the moly and bullets, so I bought some BBs. I used about a 1/4 cup of BBs, about 1/4 cup of powder in a container (a 5" long 4" dia. tube) and added 50 .357 LSWC, 160 gr. bullets and tumbled on my small rotary tumbler for 15 mintes. Seemed to cover well. Baked as usual and got a good even coating. Second batch with 125 gr. 9mms also good coating. Just a FYI...
Sunday; Like I experienced before, red is the only powder to give good coverage. Tried yellow and white, not so hot, no better than powder and bullets only...