Glock 29 Kaboom

[Intercooler]

   I'm still reading through it and trying to make something out of it all. Seems some hot .40 SwampFox was fired in a XDm with minor issues. From there it was then tried in a G29 (I know it can probably shoot .40 but... is it real safe on the upper end). Some good points in here so far.

http://www.glocktalk.com/forums/showthread.php?t=1469124

[The_Shadow]

Yea, its something that needs to be looked into!  Glad he wasn't hurt seriously!  I hope Glock will help him make things right to get his gun back in working order.  Some frames have been replaced for free or minimal cost and that allows consumers get back in the game. 

[pacapcop]

Will there be a question of rounds being from a known manufacture or a unknown manufacture?

[Yondering]

Just to clarify, this had nothing to do with firing .40 in a 10mm. He was using a .40 conversion barrel. If it had been in a 10mm barrel, pressure would have been lower anyway.

Also, not really a Kaboom, the barrel didn't blow up, he just had a ruptured case and the escaping gases blew the mag out and cracked the frame. If he'd removed the mag, it probably would have startled him but not done any damage.

It was a LW barrel, which are known for tight chamber/throat dimensions that do raise pressure. Then he fired ammo in it that was obviously way too hot, given it's performance in his XDM. No big surprise that he had a ruptured case.

3 lessons that we all should know already:
- Don't use stupid hot ammo. If you notice something weird about the ammo, stop using it.
- Some aftermarket barrels cause higher pressure with the same ammo.
- When testing hot ammo, do it one round at a time, with the mag out of the gun.

Maybe a 4th lesson - inspect your fired brass, especially when you notice something odd about that load. If he'd just fired one round and looked at the fired case, he probably could have seen signs of high pressure, and quit using it.

[Intercooler]

Wonder why it didn't pop in the Springfield?

[sqlbullet]

As Yondering points out, the Lone Wolf conversion barrel would have had much tighter dimensions.  If you make the combustion area smaller, and the friction to get the projectile moving higher, then you will increase pressure.

These rounds were already well over book.  Underwood 165 grain JHP's run 1200, and these were 1365!  That is 10mm territory!

Add in a tight chamber and bad things are gonna happen.

Another lesson to learn here that the author missed.  A 10mm with a 40 S&W barrel is still a 40 S&W.  The author was says he used his G29 since it was a 10mm and therefore I guess he assumed was magically able to handle far more pressure than the 40 S&W.  The magic of the 10mm is the extra case capacity from the longer case, not the gun being amazingly stronger.

Think of it like air-compressor tanks.  If you have a compressor with a 4 gallon tank, and compressor with an 8 gallon tank, both at 100 PSI tank pressure, you are going to fill more bike tires with the 8 gallon tank before the compressor motor kicks on than with the 4 gallon tank.

Same story for the 40 S&W and 10mm.  Both operate at pretty close to the same MAP pressure (35K vs 37.5K).  But the "tank" of 37.5K pressure on the 10mm is about twice as big as the 40 S&W.  That means that when the bullet has moved 3/4" down the barrel, there is far more residual pressure in the 10mm than the 40 S&W.

Glad the shooter is OK, and hope that he gets his gun fixed at a decent price.  But, Yondering is right, if your ammo is 15% over max book velocity for a given bullet weight in caliber, and you are seeing other signs of issues like double round feeding, etc, recognize you have a problem.  Don't try to salvage the ammo by switching to a different gun.

[The_Shadow]

I contacted the GlockTalk poster and talked with him, asked him to send me some of the ammo for pull-down... posted my findings today over at Glock Talk with the SwampFox ammo pull-down info and pictures.  Post #40
Read about the entire story at this link!
http://glocktalk.com/forums/showthread.php?t=1469124

[Intercooler]

Atomic's 180's had 8.6grs of Long Shot and this one had 10.0grs in a .40. Sounds crazy 

[P33v3]

That is a crazy amount of powder for that load. Great analysis in that post.

[The_Shadow]

The load inside the SwampFox 40S&W cartridges was 2.2 grains over the max loading listed at Hodgdon's site...





Hodgdon shows load data 40S&W 165 grain
165 GR. SIE JHP 0.400" Hodgdon Longshot COAL 1.125" listed max powder 7.8 grains, velocity 1185 fps, 33,400 PSI

The 40S&W just doesent have much room for that much more powder to have safe pressures...
Those of you who have some of SwamFox's ammo, you may want to get with someone who is a handloader to get a better understanding of what you have for safety sake!
Mike Willard is no longer with us (R.I.P.) to make things right.

added 02/07/2013
Here is the run down of all 35 SwampFox Ammo 40S&W cartridges loaded with Hodgdon's LongShot powder, as pulled-down from Deadandgone box.  Once again we wish to thank him for sharing so we can learn for this incident!


13 cartridges @ 09.6 gr / 11 cartridges @ 09.4 gr / 4 cartridges @ 09.8 gr / 4 cartridges @ 09.9 gr and 2 cartridges @ 10.0 gr

10.0 gr
09.9 gr
09.6 gr
09.4 gr
09.6 gr
09.6 gr
10.0 gr
09.6 gr
09.4 gr
09.9 gr
09.8 gr
09.8 gr
09.6 gr
09.8 gr
09.6 gr
09.8 gr
09.6 gr
09.6 gr
09.4 gr
09.6 gr
09.4 gr
09.4 gr
09.4 gr
09.6 gr
09.4 gr
09.4 gr
09.9 gr
09.8 gr
09.9 gr
09.4 gr
09.6 gr
09.6 gr
09.4 gr
09.6 gr

All loads were checked on two scales, the loads at 09.9 grains were for my balance beam RCBS 5-10 Scale these would have shown 09.8 on the digital because it only shows even numbers in the tenths column...

[The_Shadow]

For a comparison here is Underwood's offering for the 40S&W 165 grain

Bullet Weight: 165 Grains
Bullet Style: Speer Bonded Jacketed Hollow Point
Muzzle Velocity: 1200 fps
Muzzle Energy: 528 ft. lbs

[sqlbullet]

Certainly would make me nervous enough to pull down any ammo.

Of course, this is what it was advertised to be.  And for the most part there is no free lunch in internal ballistics.  You make that kind of velocity with a small case with very high pressures.

[The_Shadow]

added more data 02/07/2013
Here is the run down of all 35 SwampFox Ammo 40S&W cartridges loaded with Hodgdon's LongShot powder, as pulled-down from Deadandgone box.  Once again we wish to thank him for sharing so we can learn for this incident!

13 cartridges @ 09.6 gr / 11 cartridges @ 09.4 gr / 4 cartridges @ 09.8 gr / 4 cartridges @ 09.9 gr and 2 cartridges @ 10.0 gr

All loads were checked on two scales, the loads at 09.9 grains were for my balance beam RCBS 5-10 Scale these would have shown 09.8 on the digital because it only shows even numbers in the tenths column...

Safety Observation: Progressive presses  not so good when working at the upper end of preformance with powders that don't meter so well.

[dave1w41]

The load inside the SwampFox 40S&W cartridges was 2.2 grains over the max loading listed at Hodgdon's site...
[
Hodgdon shows load data 40S&W 165 grain
165 GR. SIE JHP 0.400" Hodgdon Longshot COAL 1.125" listed max powder 7.8 grains, velocity 1185 fps, 33,400 PSI

The 40S&W just doesent have much room for that much more powder to have safe pressures...
Those of you who have some of SwamFox's ammo, you may want to get with someone who is a handloader to get a better understanding of what you have for safety sake!
Mike Willard is no longer with us (R.I.P.) to make things right.

added 02/07/2013
Here is the run down of all 35 SwampFox Ammo 40S&W cartridges loaded with Hodgdon's LongShot powder, as pulled-down from Deadandgone box.  Once again we wish to thank him for sharing so we can learn for this incident!


13 cartridges @ 09.6 gr / 11 cartridges @ 09.4 gr / 4 cartridges @ 09.8 gr / 4 cartridges @ 09.9 gr and 2 cartridges @ 10.0 gr

10.0 gr
09.9 gr
09.6 gr
09.4 gr
09.6 gr
09.6 gr
10.0 gr
09.6 gr
09.4 gr
09.9 gr
09.8 gr
09.8 gr
09.6 gr
09.8 gr
09.6 gr
09.8 gr
09.6 gr
09.6 gr
09.4 gr
09.6 gr
09.4 gr
09.4 gr
09.4 gr
09.6 gr
09.4 gr
09.4 gr
09.9 gr
09.8 gr
09.9 gr
09.4 gr
09.6 gr
09.6 gr
09.4 gr
09.6 gr

All loads were checked on two scales, the loads at 09.9 grains were for my balance beam RCBS 5-10 Scale these would have shown 09.8 on the digital because it only shows even numbers in the tenths column...

So what we are saying here is that the max book load is 7.8 grains in this case/bullet combo but not one of these was less than 1 grain over that max?   I'll bet they perform great, until they don't and when they don't they leave you with a paperweight or injuries...  not good.

[The_Shadow]

As is with every cartridge ever developed, there are those that will push till something gives! How much is too much?...OUCH! They are looking for maximum performace throwing caution to the wind.

One thing that comes to mind in the Op's situation, pressure testing if it is done is done so in a fixed barrel fixture. While things may have been within certain limits during that testing, the dymaics of the semiauto pistols can change the way things happen thru out the pressure and ejection phases. Think of bolt action rifle vs. blowback semiautos...

Early unlocking of the barrel and slide, can actually be a cause of case failures, as the early ejection cycle is dragging the cartridge out of the chamber under pressure, increasing unsupported areas. The case expansion could actually work to further increase unsupported conditions pushing itself out of the chamber.

Primers being popped out, can move the slide back from the locked possition, the case maybe forced off the extractor hook, to be left in the chamber.

The question of the aftermarket barrel itself raises some concerns, the angles of the locking lug on the barrel in relation to the angles of the locking block in the frame, could have been different form that of stock arrangements. There is some data to support this on the various Glock gun sales sites, suggesting poor fitting and lock-up situations.

These are a few things that come to mind with the dynamics involved for the Glock and other guns.

The reason I took on this Pull-Down process, was two fold for me, I like to study what lead up to the situation and also to provide better insite, so everyone could learn something from Deadandgone's mishap with his Glock 29. After all it was his intent to post his information for these reasons of having others learn something as well.