Question about ball milling Pyrotechnics Forum
It could be the charcoal or the KNO3 holding the moisture, you would have to make sure that both ore completely dry before ball milling to get it to not clump. The recommendation is to check the ball mill every 30 minutes and/or tap the jar to break up the clumps. Personally, I don''t mill BP in the summer and wait until its winter to mill BP.