Selena said:
A certain unnamed idiot that shall remain my brother has a habit of "polishing" (for want of a better word) the primer pockets of brass before he reloads. He claims it gives a cleaner more dependable reload. Is this normal procedure or just one of my brother's many many faulty assumptions?
I think you've received a lot of responses from two "camps" in this thread but what may have gotten lost in the noise is that your question can't be answered without more information about the intended purpose for the reloaded ammo.
If I am reloading 9mm for an IDPA match where I might shoot 300 rounds and where the emphasis is on speed and economy of movement with "acceptable" accuracy at short ranges I am not going to be polishing primer pockets or even weighing individual charges. Any time I spent doing that would be much more productive if spent practicing more with "just good" ammo to improve the skills that the sport emphasizes.
On the other hand, if I was loading for a once-in-a-lifetime African hunt (or for bench rest shooting) I'd be cleaning/deburring primer pockets, sorting cases by weight and volume, trickling individual charges onto my digital scale, etc.