As previously posted, I recently bought 250 primed brass cases from an internet vendor. I received 307 cases. 
The cases were not in as good a condition as I would have hoped. They were also not uniformly sized. In order to finish processing them and making them ready to go into one of guns, I needed to resized. And that meant they needed to be lubricated. So, I lubed them up with Honady Unique, resized them and then proceeded to start wiping the lube off with a cheesecloth. This quickly brought back memories of the hand spasms that accompanied rubbing the RCBS lubricant off cases I had loaded back in the 1980's.
I elected to tumble the lube off the remaining cases.
I knew that I was risking getting tumbling media into the flash hole.
I was not worried that the media in the flash hole would "block" the ignition pulse of the primer - after all lead styphnate's explosive wavefront moves at about 16,000 fps; and I doubt any speck of walnut media is going to stand in the way of that for long. What I was worried about was media getting through the flashhole and lodging in the primer itself and "cushioning" the impact of the firing pin impact on the primer resulting in a misfire.
And, true to my concerns, of 200 rounds of brass that I tumbled, examination of the case with an otoscope (if you don't have one, it will be the best under-$20 purchase you ever spent on Amazon) revealed media in the primer on 61 of the 200 rounds (30.5%). I reasoned that if a kinetic bullet puller could remove a bullet, it could probably remove walnut media. And I was right. A single quick rap with a kinetic bullet puller was sufficient to dislodge the walnut media. A second strike was made just to be sure. Since I had 57 more primed cartridges than I had ordered, I took the liberty of testing a sample of them and they all went "bang".
So, this provides empirical confirmation that if you tumble primed brass in dry meda, some may get into the flashhole and/or primer. Whether this would interfere with the primer igniting the powder remains an open question. But, removal of the media can be effectively accomplished with a kinetic bullet puller.
If anyone else has had this question lingering in the back of their mind, I hope this helps. Also, if you have tumbled primed brass and had it cause a problem, I would like to hear about it - and the circumstances leading up to the misfire.
Thanks.
The cases were not in as good a condition as I would have hoped. They were also not uniformly sized. In order to finish processing them and making them ready to go into one of guns, I needed to resized. And that meant they needed to be lubricated. So, I lubed them up with Honady Unique, resized them and then proceeded to start wiping the lube off with a cheesecloth. This quickly brought back memories of the hand spasms that accompanied rubbing the RCBS lubricant off cases I had loaded back in the 1980's.
I elected to tumble the lube off the remaining cases.
I knew that I was risking getting tumbling media into the flash hole.
I was not worried that the media in the flash hole would "block" the ignition pulse of the primer - after all lead styphnate's explosive wavefront moves at about 16,000 fps; and I doubt any speck of walnut media is going to stand in the way of that for long. What I was worried about was media getting through the flashhole and lodging in the primer itself and "cushioning" the impact of the firing pin impact on the primer resulting in a misfire.
And, true to my concerns, of 200 rounds of brass that I tumbled, examination of the case with an otoscope (if you don't have one, it will be the best under-$20 purchase you ever spent on Amazon) revealed media in the primer on 61 of the 200 rounds (30.5%). I reasoned that if a kinetic bullet puller could remove a bullet, it could probably remove walnut media. And I was right. A single quick rap with a kinetic bullet puller was sufficient to dislodge the walnut media. A second strike was made just to be sure. Since I had 57 more primed cartridges than I had ordered, I took the liberty of testing a sample of them and they all went "bang".
So, this provides empirical confirmation that if you tumble primed brass in dry meda, some may get into the flashhole and/or primer. Whether this would interfere with the primer igniting the powder remains an open question. But, removal of the media can be effectively accomplished with a kinetic bullet puller.
If anyone else has had this question lingering in the back of their mind, I hope this helps. Also, if you have tumbled primed brass and had it cause a problem, I would like to hear about it - and the circumstances leading up to the misfire.
Thanks.
