Dowen

It's only happening with round nose bullets as they stack in a zig zag pattern in the tube, meaning the weight above pushes down on the left or right side causing the base to jam against the side. Flat nose bullets stack neatly on each other so the weight is directly above and hence the base is not being tilted to a side, so no jam. I chamfered which reduced the frequency but may have to chamfer deeper to totally stop the problem.