Leo Ammo Bullet Set-back Warning

[Carlos]

I cannot vouch for the authenticity of the following memo - although from the info it contains, it appears legit. It has been re-produced as posted on another forum & thought it might be of interest to the 40 reloading comunity. Notice that it seems imply that "compressed powder" has something to do with overpressure - when in fact we all know that it is a set-back's REDUCED CASE CAPACITY that causes overpressure conditions:

"The following bulletin was received from the New Jersey State Police - Officer Safety Division

Date: February 23, 2007

Continuous reloading and chambering of the same round may cause catastrophic failure in semiautomatic handguns.

The Security Force at the Los Alamos National Laboratory in Los Alamos, New Mexico, recently reported on the catastrophic failure of a semiautomatic handgun when it was fired. The internal explosion caused the frame to break while the slide and barrel separated from the weapon and traveled down range. No one was injured in the incident. An investigation revealed that security personnel were repeatedly charging the same round of ammunition into the chamber.

Technical personnel at Glock Inc. advise that repeated chambering of the same round may cause the bullet to move deeper into the casing, further compacting the propellent. When a normal cartride is fired, the firing pin his the primer, igniting the propellant. When the propellant burns, the gas pressure drives the bullet out of the case and down the barrel. However, if the propellant has been compact, the pressure may increase beyond the gun's specifications, causing the weapon to break apart. Sigarms Inc's peronnel confirm that reloading the same round five or six times will cause the problems, noting that reloading the same round even once will void their warranty. Both manufacturers stress that the problem is not with the gun, but with chambering the same round repeatedly.

The NJ Regional Operations Intelligence Center urges all law enforement officers not to chamber the same round when loading their weapons.

***For example, when you clean your weapon, most of us drop the magazine and then pull the slide back thereby ejecting the round in the barrel. After cleaning the weapon many of us will return the "same" round to the barrel that we initially extracted. Each time the slide slams forward on that same round it seats it deeper into the cartridge. Apparently, by seating the round deeper into the cartridge, it creates greater pressure when the round is intentionally detonated by a firing pin strike and is causing weaopn's to explode."

I use the "U" die to avoid any chance of set back. Never had a KB or separation. in 7 yrs of reloading.

Regards,

C.

[G-ManBart]

Carlos,

I'm not too far from Los Alamos and know some guys at the security division there. I'll try giving them a call to see if the story is true.

I (WAS) a little bit skeptical that chambering a round a bunch of times really causes setback in factory ammo, but it certainly could be possible and did happen with two loads I tried per XRe's suggestion. I am 100% in agreement that it's not a good idea to rechamber the same round over and over. My dad had one of his troops shot (Army MP) because a constantly rechambered .45 round (this was in 1961) had a groove worn in the rim....guy and his partner decide to play quick draw on the gate late one night and when they "cleared" the guns, didn't notice the round left in the chamber when the extractor slipped through that groove...ouch.

I will rechamber a round once or twice and that's it. We're directed to shoot up our carry ammo during qualifications every quarter to prevent ammo problems. I do know that when I was on active duty the same round would get chambered, cleared, chambered cleared etc for ages as they issued you your gun and mags every shift. When we qualified, we took empty guns to the range and used the mags and ammo at the range. I can't imagine how many times some duty rounds were rechambered and I never heard of a KB because of it....personally I rotated my ammo within the mags so they didn't get chewed up so badly.

Edited March 8, 2007 by G-ManBart

[XRe]

I'm a little bit skeptical that chambering a round a bunch of times really causes setback in factory ammo, but it certainly could be possible.

Try it and see... Take a factory round. Measure OAL. Lock the slide back on the pistol and then drop it on that round. Repeat 10 times. Re-measure OAL. You might be surprised...

I've had factory ammo shorten up after only one or two times up into the chamber (WWB 165gr .40, most notably...) - enough that I could visibly see it right away....

[G-ManBart]

Try it and see... Take a factory round. Measure OAL. Lock the slide back on the pistol and then drop it on that round. Repeat 10 times. Re-measure OAL. You might be surprised...

I've had factory ammo shorten up after only one or two times up into the chamber (WWB 165gr .40, most notably...) - enough that I could visibly see it right away....

I don't know why I didn't think to try it myself, but you're right....tried some Federal Hydra-shoks I had lying around and some Cor-Bon and they both shortened up enough that I noticed it after about four or five tries. I would love to get my hands on some of the military issue ball ammo that we carried way back when because I know that stuff got chambered many, many times and never saw any that looked shorter. Guess I'm glad I don't chamber my carry rounds more than once or twice...now that will be ONCE! Thanks.

[XRe]

I would love to get my hands on some of the military issue ball ammo that we carried way back when because I know that stuff got chambered many, many times and never saw any that looked shorter.

I may be wrong - but I believe most/all of the milspec stuff has an asphalt sealer that keeps moisture out of the case? That might also prevent setback more than just a straight crimp... It would be interesting to try out, though...

[G-ManBart]

Here's a slight update. Our guys that are at Los Alamos every day hadn't heard anything about it. They were going to make a couple of calls and see what they could find out.

I was talking about it with one of the guys in the office who's a firearms instructor and we decided to test it out some more. Using issue Speer Gold Dot 165gr duty ammo, I chambered the same round ten times in my Glock 27 (backup) with zero setback...measured. I then chambered it five times in my STI (which caused the setback I previously mentioned) and it measured the same as before...no setback. Strange that Federal Hydra Shoks and Cor-Bon setback after as little as four chamberings, but nothing with the Speer stuff. I was thinking that the lighter slide on the 27 might not have had enough oomph to cause setback, which is why I tried the STI. Tomorrow I'm going to try that same round in one of my Glock 22s since that's my primary carry gun to see how that turns out...I didn't use the 22 today because I didn't have an empty mag handy and didn't feel like messing with unloading/loading 15 rounds:-) Regardless, it's all very interesting!

[DougCarden]

I see it in our .40 Sigs with CCI 165gr jhp Gold Dots.....FWIW

DougC

[Shoot-4-Ever]

I'm far from being an expert in such things but here are some of my thoughts that I have had in the last year or two after hearing about this problem.

First off, how many time have I dropped a round on a hard surface and picked it up and looked to see that there was not a ding in the lead and carried on as usual. Now days, if I drop one, I line them up and compare with a straight edge to see if there is a deep seat in the crowd. Sometimes I have put it in my pocket with plans to measure the OAL when I get back home. Then weeks later, I reach into a small pocket in my shooting vest and find an extra round...oh, look I found a stray... then load it up and shoot it.

I don't have any idea if dropping a rounds on the floor would be anything like slamming the slide a time or two.

The other thing I have done (usually with a clean gun) when reloading, is drop the round (often the same one) back into the chamber and then control the closing of the slide a little. Then insert mag, this way I have max load. Now I don't carry a semi for self protection or as a duty weapon so maybe I have a different way of looking at the this method. Back in my day, I carried a revolver as a duty weapon and had speed loaders in a leather pouch on the belt. We always shot them up as well as the six rounds in the cylinder when qualifying or practicing because they get very dirty (dust lint etc.) from day to day carry. I would think shooting up your carry ammo would be standard procedure.

Just a my different point of view, not to say any of this it's right or wrong, just conversation FWIW.

[shred]

FWIW, as a test to see if dropping rounds on the ground hurt accuracy, I dropped one of my reloads nose-down onto concrete ten times from about 5 feet up. The JHP was a little dinged, but otherwise it was in good shape. It hit the 6" plate at 40 meters, so accuracy was still good too. I'd guess that chambering is probably worse than dropping, unless you dropped them base-first.