This surprises me. I've reloaded literally thousands of 9mm rounds on my Loadmaster (not to mention many thousands more of 38 Spec, 40 S&W & 45 ACP) and have NEVER ripped a rim off any of them. However, I am religious about tumbling my brass sparking clean before it goes into the sizing die and I think this helps a lot. It only stands to reason that clean cases will create a lot less friction than cases that are soiled with a buildup of powder residue, range dust and anything else they might pick up in the shooting process. The thought of having to clean the lube off hundreds and hundreds of loaded rounds does not appeal to me in the least.