No. The Sinclair sizing mandrel is basically a die that has different caliber mandrel's. I use it to size the inside neck diameter(basically bringing it back to caliber). I use it instead of the sizing ball on a regular sizing die. That way the expander ball on the regular die does not affect the brass at all. I think the expander ball is the "ROOT OF ALL EVIL"-so I get rid of them. IMO there is no way the expander ball can stay perfectly centered in the case, and I also believe it has an affect on the shoulder when you are resizing the inside of the neck.

I also use the mandrel after I clean my brass, and I use sizing wax. I do not get any friction when I do this.

I definitely agree that runout is very important, but I am more concerned with chamber alignment. And since I shoot all my rifle's in single shot mode, I seat all my bullet's into the lands.

BC is right when you have to worry about bullet jump-but bullet jump does not concern me. I do have bulet jump in my lever actions, but I cast all my bullet's for my lever's, and quite honestly minute of deer accuracy is all I worry about in my lever's. Tom.