I understand the concern. It was mine when I cleaned pockets. I can't shoot the difference. When processing from 100-400 cases in a batch the cleaning process add a bit of time. SS pin tumbling worked great....when I cleaned my brass. I only rinse it now to get the dust off prior to processing. More time savedI still clean pockets because I haven't tested without cleaning and it is a very quick task. My concern is the carbon might mess with the consistency of the primer crush.
