Primer Pocket Cleaning-The Great Debate

No adverse impact that I have ever been able to detect, at least out to 600 yards, in my personal testing. Current priming compounds leave less residue than in the past. If the cases are pre-1960 military I wet-clean the primer pockets to remove any corrosive residue so it doesn't get launched down the bore, but brass like that is uncommon anymore.

I'm not a professional reloader, but I play one on TV. Here are 2 things I've noticed...

• Like the post above, I've never noticed any measurable difference in performance between cleaned and un-cleaned primer pockets. But then again, 95% of my reloading is for short distance "practical pistol" where the accent is on accuracy and reliability.

• Maybe it's an illusion, but I've noticed (as opposed to scientifically measured) that the primer pockets do not progressively fill with "primer muck". (That's a technical term we TV professionals use to described the
residue left in the primer pockets.) That is to say, the situation rarely gets worse over the life of the cartridge case. I have therefore "assumed" (and there's a dangerous word if there ever was one) that "muck" is the by-product of the powder + primer, and not solely left by the primer. One might therefore reach the dangerous conclusion that modern reloading powders burn cleaner than the factory stuff. At any rate, however bad the situation looks on first de-capping, it rarely gets worse and often appears to get better over time.

Suggestion: It would be an easy and very interesting experiment to photo document the primer pockets of 5 pieces of brass over 10 reloads. IMHO, this is going to give you the only definitive answer for your type shooting with your powders and primers.

Hope this helps!

Bench rest shooters clean the primer pockets of their brass and even ream out the flash holes using a numbered drill bit so the flash hole is the exact same size on all their brass.  They are anal about consistency.

Being a typical shooter I'm more interested in a lot of bangs for my time at the reloading bench.  I figure that whatever gravity doesn't pull out of the primer pocket during depriming is meant to stay in the pocket.  The decapping pin ensures a complete path in the flash hole.'

Back before progressive presses, when I used a Rockchucker, I would deprime the cases, then tumble them in the tumbler, and before I would prime the cases I had to inspect each flash hole because a piece of tumbling media usually got stuck in the flash hole.  If this stayed there it would probably do bad things to case pressure and ignition.

Summary - don't worry about it.  I usually loose the brass before the primer pocket would get too bad.