overuse of chambered rounds in pistols
I recieved this from a friend , hope it will help some folks to be more careful and safe, sorry if the photos don't load,but it is very informative anyway, Bob
Set-Back" Suspected
Don't be cheap! Rotate that service or A report has eminated from Los Alamos National Laboratory concerning a Glock Model 22 pistol which disassembled under duress while being fired by one of their firearms instructors. The cause is probably related to their .40 S&W ammunition which is issued to guard force personnel on a daily basis and then returned.
It would appear that some ammunition is used to load the pistol when going on duty by being issued in a magazine with one (1) round in it. This round is used to charge the chamber and then, presumably, a fully-loaded magazine is inserted into the pistol.
In the photo at right, one can see a .40 S&W round in the magazine which appears to have the bullet seated further than normal into the case.
It appears that these "single-loaded" rounds are unloaded and kept segregated when turned in at the end of the shift, whereupon those rounds are used for single loading again... and again.
The round involved in the catastrophic failure of this particular Glock is said to have been loaded 45 times in 30 days.
Note the virtually intact feed-ramp, and just where the barrel failed... highly uncommon where no bore obstruction is present.
While the report mentions something about a possible bore obstruction contributing to the problem, there are no supporting details. The barrel let go forward of the chamber and "blew out" downward, removing the dust cover from the Model 22's frame.
No photo of the slide has been included as it doesn't display any obvious damage.
What is commonly known, and is referenced in the report, is that continuous loading of the same round(s) will eventually create an excessive pressure situation as the projectile is driven deeper into the case due to repeated contact with the feed ramp under force. As a .45 ACP round operates in the 21,000 psi range, projectile set-back may not create an over-pressure problem. When the S&W .40 cartridge, which operates at the 31,700-33,600 psi levels, several thousandths of set-back could generate enough of a pressure spike needed to disassemble the pistol.
The report states that the shooter was not hurt and that the frame (less the dust cover) and magazine remained intact, while the barrel and slide parted from the pistol and traveled some distance.
The Instructive Part
Thou shall not horde thy ser-vice rounds, replac-ing those in thy magazine at least once each month, the pre-ferred method be-ing "Front sight... trig-ger... P R E S S!"
Rotate pistol ammunition regularly and routinely, especially those rounds subjected to recurring administrative unloading and reloading.
An excellect method of doing this is to start off one's practice or qualification session on the range by shooting all the rounds you've been using as duty or "carry" ammo since one's last range session.
Additional Thoughts...
Damn! The providing source's declamations to the contrary, that Model 22's barrel really does look like the bore had been obstructed, which fact was also observed and commented upon by my colleagues Charlie Petty and Patrick Sweeney.
My friend Ernest Durham1, an engineer with ATK/Speer, had this to say several years ago, albeit in a slightly different context:
There are a ton of folks out there who constantly load and unload the top round in their magazine, and then complain that the overall length is changing. In fact, such battery of the case neck can weaken it so much, that the shrinking tendency will rebound, and all of a sudden, the bullet is gone!
Where? Down the bore! The darn things pop out of the case upon chambering and fly down the bore to create an obstruction for the next round.
It will be interesting to see if the folks at Los Alamos pursue this event for a definitive causing factor.
The Official DOE Report2
On 12 December 2006, at 0845, at Technical Area 72, Firing Range 1, a Glock 22 handgun exploded in the hands of a Protective Technology Los Alamos (PTLA) firearms instructor as he fired the handgun.
The firearms instructor was not injured, but felt some soreness in his right hand. He noted that the force of the handgun pushed his right thumb back. The handgun shattered into several pieces; the pieces flew everywhere and eventually landed on the ground. He safed the remaining box of ammunition and then reported the event to his management. As a precaution, the firearms instructor was taken to the Laboratory's occupational medicine facility for evaluation. He was evaluated, released to return to work with no restrictions, and scheduled for a follow-up evaluation the next day.
The instructor was preparing for a training exercise and was the only person on thefiring range at the time of the event. He wore the prescribed personal protective equipment for firearms use (safety glasses, armored vest, head and hearing protection, nomex gloves, a long sleeve shirt, and safety boots.)
The handgun has been secured in the PTLA armory. PTLA management has initiated an internal investigation.
Subsequent preliminary PTLA review indicated that a possible combination of excessive pressure and a bore obstruction contributed to the explosion.
The rounds used during this training event were duty rounds recently removed from service that had been used in a magazine containing a single round by PTLA forces. The single rounds of ammunition designated for initial loading in Glock 22 handguns are used on a daily basis and the one round of ammunition is typically loaded 45 times over a 30-day period. The frequent loading of the rounds continually pounds the ammunition into the chamber, which in turn recesses the bullet further into the casing. Over time and use, the projectile is seated deeper into the cartridge case contributing to an increase inpressure upon firing.
Because the event revealed lessons learned that may be pertinent to the DOE complex, the Institutional Facilities and Central Services Facility Operations Director deemed the event reportable as a management concern.
Background:
The firearms instructor had used the handgun for about five years.He noted that the last time he used the handgun was on 7 December 2006, and had cleaned and secured the handgun that same day. Before the event, the instructor had fired the handgun five times. After the event, the instructor noticed that one bullet remained in the handgun. Other PTLA firearms instructors noted that this is the first time this type of event has occurred with Glock handguns at PTLA.
Cause Description:
Operating Conditions:
Training Exercises Activity Category:
Training Immediate Action(s): As a precaution, the firearms instructor was taken to LANL occupational medicine for evaluation. He was evaluated and released to return to work with no restrictions. He returned for a follow-up evaluation on 13 December 2006.
The handgun has been secured in the PTLA armory.
PTLA management has initiated an internal investigation.
The remaining box of single round loading magazine ammunition has been removed from service and will be properly disposed of.
PTLA will not use defective rounds for training and will dispose of them.
FM Evaluation:
DOE Facility Representative Input:
DOE Program Manager Input:
Further Evaluation is Required:
No Division or Project:
Protection Technology Los Alamos Plant Area: TA72, Firing Range 1
System/Building/Equipment: Glock 22 Handgun Facility
Set-Back" Suspected
Don't be cheap! Rotate that service or A report has eminated from Los Alamos National Laboratory concerning a Glock Model 22 pistol which disassembled under duress while being fired by one of their firearms instructors. The cause is probably related to their .40 S&W ammunition which is issued to guard force personnel on a daily basis and then returned.
It would appear that some ammunition is used to load the pistol when going on duty by being issued in a magazine with one (1) round in it. This round is used to charge the chamber and then, presumably, a fully-loaded magazine is inserted into the pistol.
In the photo at right, one can see a .40 S&W round in the magazine which appears to have the bullet seated further than normal into the case.
It appears that these "single-loaded" rounds are unloaded and kept segregated when turned in at the end of the shift, whereupon those rounds are used for single loading again... and again.
The round involved in the catastrophic failure of this particular Glock is said to have been loaded 45 times in 30 days.
Note the virtually intact feed-ramp, and just where the barrel failed... highly uncommon where no bore obstruction is present.
While the report mentions something about a possible bore obstruction contributing to the problem, there are no supporting details. The barrel let go forward of the chamber and "blew out" downward, removing the dust cover from the Model 22's frame.
No photo of the slide has been included as it doesn't display any obvious damage.
What is commonly known, and is referenced in the report, is that continuous loading of the same round(s) will eventually create an excessive pressure situation as the projectile is driven deeper into the case due to repeated contact with the feed ramp under force. As a .45 ACP round operates in the 21,000 psi range, projectile set-back may not create an over-pressure problem. When the S&W .40 cartridge, which operates at the 31,700-33,600 psi levels, several thousandths of set-back could generate enough of a pressure spike needed to disassemble the pistol.
The report states that the shooter was not hurt and that the frame (less the dust cover) and magazine remained intact, while the barrel and slide parted from the pistol and traveled some distance.
The Instructive Part
Thou shall not horde thy ser-vice rounds, replac-ing those in thy magazine at least once each month, the pre-ferred method be-ing "Front sight... trig-ger... P R E S S!"
Rotate pistol ammunition regularly and routinely, especially those rounds subjected to recurring administrative unloading and reloading.
An excellect method of doing this is to start off one's practice or qualification session on the range by shooting all the rounds you've been using as duty or "carry" ammo since one's last range session.
Additional Thoughts...
Damn! The providing source's declamations to the contrary, that Model 22's barrel really does look like the bore had been obstructed, which fact was also observed and commented upon by my colleagues Charlie Petty and Patrick Sweeney.
My friend Ernest Durham1, an engineer with ATK/Speer, had this to say several years ago, albeit in a slightly different context:
There are a ton of folks out there who constantly load and unload the top round in their magazine, and then complain that the overall length is changing. In fact, such battery of the case neck can weaken it so much, that the shrinking tendency will rebound, and all of a sudden, the bullet is gone!
Where? Down the bore! The darn things pop out of the case upon chambering and fly down the bore to create an obstruction for the next round.
It will be interesting to see if the folks at Los Alamos pursue this event for a definitive causing factor.
The Official DOE Report2
On 12 December 2006, at 0845, at Technical Area 72, Firing Range 1, a Glock 22 handgun exploded in the hands of a Protective Technology Los Alamos (PTLA) firearms instructor as he fired the handgun.
The firearms instructor was not injured, but felt some soreness in his right hand. He noted that the force of the handgun pushed his right thumb back. The handgun shattered into several pieces; the pieces flew everywhere and eventually landed on the ground. He safed the remaining box of ammunition and then reported the event to his management. As a precaution, the firearms instructor was taken to the Laboratory's occupational medicine facility for evaluation. He was evaluated, released to return to work with no restrictions, and scheduled for a follow-up evaluation the next day.
The instructor was preparing for a training exercise and was the only person on thefiring range at the time of the event. He wore the prescribed personal protective equipment for firearms use (safety glasses, armored vest, head and hearing protection, nomex gloves, a long sleeve shirt, and safety boots.)
The handgun has been secured in the PTLA armory. PTLA management has initiated an internal investigation.
Subsequent preliminary PTLA review indicated that a possible combination of excessive pressure and a bore obstruction contributed to the explosion.
The rounds used during this training event were duty rounds recently removed from service that had been used in a magazine containing a single round by PTLA forces. The single rounds of ammunition designated for initial loading in Glock 22 handguns are used on a daily basis and the one round of ammunition is typically loaded 45 times over a 30-day period. The frequent loading of the rounds continually pounds the ammunition into the chamber, which in turn recesses the bullet further into the casing. Over time and use, the projectile is seated deeper into the cartridge case contributing to an increase inpressure upon firing.
Because the event revealed lessons learned that may be pertinent to the DOE complex, the Institutional Facilities and Central Services Facility Operations Director deemed the event reportable as a management concern.
Background:
The firearms instructor had used the handgun for about five years.He noted that the last time he used the handgun was on 7 December 2006, and had cleaned and secured the handgun that same day. Before the event, the instructor had fired the handgun five times. After the event, the instructor noticed that one bullet remained in the handgun. Other PTLA firearms instructors noted that this is the first time this type of event has occurred with Glock handguns at PTLA.
Cause Description:
Operating Conditions:
Training Exercises Activity Category:
Training Immediate Action(s): As a precaution, the firearms instructor was taken to LANL occupational medicine for evaluation. He was evaluated and released to return to work with no restrictions. He returned for a follow-up evaluation on 13 December 2006.
The handgun has been secured in the PTLA armory.
PTLA management has initiated an internal investigation.
The remaining box of single round loading magazine ammunition has been removed from service and will be properly disposed of.
PTLA will not use defective rounds for training and will dispose of them.
FM Evaluation:
DOE Facility Representative Input:
DOE Program Manager Input:
Further Evaluation is Required:
No Division or Project:
Protection Technology Los Alamos Plant Area: TA72, Firing Range 1
System/Building/Equipment: Glock 22 Handgun Facility
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