I borrowed this from another small but informative forum. I had never considered this as a potential problem. Good food for thought. Quote; > THE FOLLOWING TRAINING ADVISORY WAS FORWARDED FROM GWINETT COUNTY POLICE DEPARTMENT – LAWRENCEVILLE, GA > > In September of this year a GCPD officer was involved in a situation which quickly became a use of deadly force incident. When the officer made the decision to use deadly force, the chambered round in his duty pistol did not fire. Fortunately, the officer used good tactics, remembered his training and cleared the malfunction, successfully ending the encounter. > > The misfired round, which had a full firing pin strike, was collected and was later sent to the manufacturer for analysis. Their analysis showed the following: “…the cause of the misfire was determined to be from the primer mix being knocked out of the primer when the round was cycled through the firearm multiple times”. We also sent an additional 2,000 rounds of the Winchester 9mm duty ammunition to the manufacturer. All 2,000 rounds were successfully fired. > > In discussions with the officer, we discovered that since he has small children at home, he unloads his duty weapon daily. His routine is to eject the chambered round to store the weapon. Prior to returning to duty he chambers the top round in his primary magazine, then takes the previously ejected round and puts in back in the magazine. Those two rounds were repeatedly cycled and had been since duty ammunition was issued in February or March of 2011, resulting in as many as 100 chambering and extracting cycles. This caused an internal failure of the primer, not discernible by external inspection. > > This advisory is to inform all sworn personnel that repeated cycling of duty rounds is to be avoided. As a reminder, when loading the weapon, load from the magazine and do not drop the round directly into the chamber. If an officer’s only method of safe home storage is to unload the weapon, the Firearms Training Unit suggests that you unload an entire magazine and rotate those rounds. In addition, you should also rotate through all 3 duty magazines, so that all 52 duty rounds are cycled, not just a few rounds. A more practical method of home storage is probably to use a trigger lock or a locked storage box. > > FURTHER GUIDANCE: > > The primer compound separation is a risk of repeatedly chambering the same round. The more common issue is bullet setback, which increases the chamber pressures often resulting in more negative effects. > > RECOMMENDATION: > > In addition to following the guidance provided above of constantly rotating duty ammunition that is removed during the unloading/reloading of the weapon, training ammunition utilized during firearm sustainment and weapon manipulation drills, should also be discarded if it has been inserted into the chamber more than twice. This practice lessens the likelihood of a failure to fire or more catastrophic results.
Thanks greyhawk. It would have never occured to me that the primer could be compromised by that sequence of events. I do the same thing with my carry pistol but not every night like the subject officer. I guess I should change my ways just a little to insure that doesn't happen. When I used a 1911 for open home carry I did have a couple incidents of bullet setback when loading the top round into the chamber from the mag. They were the Federal hydra-shock personnel defense rounds back around 2004. Just barely noticed it as the slide went forward.
grey, that's some good information you posted, and something to keep in mind if you unload and reload your pistol. a loose primer is one thing we would never ever probably think to cause a round to fail to fire. thanks for the heads up.
As I read through the advisory, it seemed to indicate that the compound in the primer failed. My understanding is that the primer compound is a plaster type substance. If the compound becomes a powder due to repeated mishandling, then it will fail to ignite when the cup impacts the anvil. Correct me if I'm wrong but that was my interpretation. Grey
grey, i am not for sure either, but that sounds reasonable and could very well be what happened. all in all, very good article and shed some light on how we handle our ammo in the future. thanks for posting it.
I believe, but am not positive, that describing primer compound as a plaster type material is fairly accurate. I think it's a powder type material that is mixed with a binder in a solvent for application. So when it's dry it would be a brittle substance subject to shock damage. Another reason to choose revolvers.
I use the same practice just not on a daily cycle. I do however use my loaded magzines at the range then reload with fresh ammo when finished. This article sheds some interesting thoughts. However they did not say his second round miss fired or failed either.