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digiadaamore
02-02-2012, 10:48 PM
Hey guys all the discussion on the web about rechambering rounds has me wondering, are there any documented cases duty ammo failing to expand etc... from rechambering

digiadaamore
02-02-2012, 11:29 PM
Hey guys all the discussion on the web about rechambering rounds has me wondering, are there any documented cases duty ammo failing to expand etc... from rechambering

Thinking about it perhaps a better question is are there any documented shootings where a round that had been rechambered functioned as inrended

DocGKR
02-03-2012, 12:35 AM
There are numerous well documented incidents where duty ammo that had been repeatedly re-chambered failed to fire--both in training, OIS incidents, and in OCONUS combat.

barstoolguru
02-03-2012, 12:43 AM
There are cases where ammo has blown guns apart because gun powder broke down and did not fill the casing and exploded. rechambering the same round over and over will set the bullet back in the brass and cause higher pressure. Rotate your ammo out and shoot up the carry ammo and replace it

TGS
02-03-2012, 11:07 AM
There are cases where ammo has blown guns apart because gun powder broke down and did not fill the casing and exploded.

I'd appreciate it if you could provide some examples of this happening.

digiadaamore
02-03-2012, 12:42 PM
Ok guys let me be more specific. I know all about the issues with ar's and primers, i ask purely about 9,40,45. And i know about kb's from setback, what i mean is cases not with setback but purely terminal bullet performance. Cases where a duty hp turned into fmj from damage caused by rechambering

fuse
02-03-2012, 02:48 PM
Anything is possible. But the main issue with pistol rounds is indeed setback.

Also, that would be very tough to impossible to prove, since perfectly fine JHPs sometimes don't expand like we'd like them to when shot into actual alive threats, and all the variables of body type and clothing they come with.

DocGKR
02-03-2012, 04:49 PM
The problems with re-chambering rounds is NOT terminal performance, it is a failure to fire. This has been documented to occur in handguns, as well as AR15's.

As written at LF by "03humpalot":


"I have relayed this story to a few of you before but here it is again. Pay attention to what DocGKR posted above because it could very well save your life.

My first shooting in Iraq i threw my M4A1 on semi and ATTEMPTED to fire a controlled pair (First round functioned striking the threat and the second round did not function) i then transitioned to my secondary (glock 19 shooting ball) and had a failure to fire on my first round. Eek...i was Waaaaaay behind the power curve at this point.

At this point i was contemplating all of my various bad life decisions which had lead me to that point in my life and grabbed an M240B and solved the problem.

I AM VERY LUCKY TO STILL BE UPRIGHT AND BREATHING TODAY....the cause of these malfunctions you ask?

Repeated chamberings of the same ammo.

I made a decision that day that my life was more important than following archaic rules written by those who sit behind desks and started shitcanning rounds after i was forced to clear weapons on U.S. Military installations.

The .gov can fuckin bill me.

Just FYI fellas."

JohnO
02-03-2012, 05:46 PM
I recently read of an incident where the repeated rechambering of a duty round resulted in a Failure to Fire. Autopsy on the effected round revealed that the primer compound had exited to primer cup through the flash hole. Therefore the firing pin strike resulted in a dud.

TGS
02-03-2012, 06:54 PM
Good lord, how many times does the OP have to write that he knows about the failure to fire and setback issues.......

I would agree with Fuse. You might want to look at the problems that Winchester had with their Ranger line during one batch. The cuts for the HP petals were not deep enough due to old tooling, causing the rounds to fail to expand. I think that's a good enough reason to believe that JHP construction is very sensitive to proper form, construction, ect....and that a damaged HP with a deformation would fail to work properly.

Hope that helps.

digiadaamore
02-03-2012, 10:52 PM
The problems with re-chambering rounds is NOT terminal performance, it is a failure to fire. This has been documented to occur in handguns, as well as AR15's

Thats enough for me! thank you doc


Good lord, how many times does the OP have to write that he knows about the failure to fire and setback issues.......

Thanks for that

Chuck Haggard
02-05-2012, 03:03 AM
I have seen a few JHPs that were beat up enough that I am convinced they likely wouldn't expand. Fortunately we found such ammo during in-service shoots when we used up the duty ammo in training and issued new stuff, never had an OIS with such a bullet to test the theory.

HCM
02-06-2012, 01:10 PM
Hey guys all the discussion on the web about rechambering rounds has me wondering, are there any documented cases duty ammo failing to expand etc... from rechambering

Received via another Agency. The incident occurred in September, 2011.

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 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.

SOD 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

TGS
02-06-2012, 04:13 PM
My god......

facepalm.


Does anyone even read his question?

digiadaamore
02-06-2012, 10:35 PM
My god......

facepalm.


Does anyone even read his question?

I know. It ok though, i believe its just that for people like us it gets hard listening to uninformed individuals constantly we start to standardize our responses to fit as much info without explanation as possible.

barstoolguru
02-06-2012, 11:11 PM
this is from another web site


Had a Kaboom a few weeks ago. Glock 30 with factory ammo. Indoor range. I fired 8 rounds from a 10 round magazine, everything felt and functioned normally. On firing the 9th round, I felt a stunning impact to my hands and face. It took me a few seconds to realize my pistol was now laying on the ground in front of me, and I was bleeding from both hands, forehead, nose and cheek. Fortunately, all the wounds proved to be superficial, the most serous was to my right hand, where the top layer of skin in 1/4" by 1" area of the web between the thumb and forefinger was blown off and powder residue embedded. A small piece of shrapnel 1/8" by 1/3" was removed from my forehead from just under the skin. Both hands were bruised and sore for a few days.

The pistol frame was cracked on both sides, the barrel split in the chamber area, and small parts, like the magazine release and spring were missing.
This pistol had maybe 3-4 thousand rounds through it, all jacketed bullets, never any lead. It had been recently cleaned and inspected, with everything appearing normal.

The pistol was examined by the rangemaster and gunsmith at the scene, and their conclusion was an ammo problem. I sent the pistol and remaining ammo from that box back to the ammo manufacturer for examination. Without admitting any wrongdoing, and claiming they found nothing wrong with the ammo, they sent me a check for the replacement cost of the pistol. In the desire to avoid any legal issues, and being satisfied with their response, I will not name the ammo manufacturer.

Before sending the ammo back, I pulled a few of the bullets and examined the powder myself, including weighing the powder charge. Without knowing what powder the factory uses I can't know the correct amount, but the charges I weighed were in line with powder weights listed in reloading books, nothing approaching a double charge. However, with my admittedly unscientific examination of the powder with a magnifying glass, there seemed to be variation in the size of the powder grains, some much smaller than others.

The only exlaination that I can come to is that the kaboom may have been caused by firing ammo that had been carried in the saddlebags of my motorcycle for thousands of miles. The vibration of the bike, the bouncing around from potholes, etc. caused the powder to break down into smaller granules, which will ignite and burn faster that the would otherwise. I am familiar with this process, as my former occupation was an operator in a coal fired powerplant, and it was well known that different size particles of the same fuel would burn at different rates, and that very fine particles will burn much faster than larger particles.

So, what does all this mean? I know it has been recommended here and elsewhere to rotate carry ammo, mostly to avoid bullet setback due to repeated chambering of the same round. I think here is another reason to rotate ammo. I'm sure this example is an extreme case, and few people will carry their ammo thousands of miles, on a bike or car before firing it. I know any ammo that I carry for long will be used in the next practice session, and replaced with fresh






http://www.defensivecarry.com/forum/defensive-ammunition-ballistics/133025-not-rotating-your-ammo-kaboom-long.html

TGS
02-06-2012, 11:53 PM
I know. It ok though, i believe its just that for people like us it gets hard listening to uninformed individuals constantly we start to standardize our responses to fit as much info without explanation as possible.

What's amazing is that even after openly chatting about this, it still happens. Now I'm just flat out laughing! :D

HCM
02-07-2012, 10:03 AM
Duh ! That what i get for multi-tasking ......