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Glock 29 kaboom

29K views 142 replies 37 participants last post by  Taterhead 
#1 · (Edited)
Kaboom happened today...kaboom part at the end of this important part of the story


hot ammo question
First, apologies as this relates to a 40 cal xdm. Why I am asking here is that it relates to some ammo Mike Willard made up for me before he passed, a scalding hot 165 gd at 1325 fps. What happened to me yesterday I have never seen or heard of before, so since this forum deals with issues of high speed and high pressure and all the surrounding issues, I come here. I have a g29 and am used to firing hot loads...but anyway...

Here's what happened. I was just going to shoot my xdm because I was bored, and it had been a while since I shot it, so I carried it outside with a few of Mike's rounds in it. Full mag.

I fired the first round, and enjoyed the feel. I looked down on the ground, and an unfired shell was on the ground. I shot a few more rounds, and went inside. The uncertainty of what just happened made me pause and think. So I loaded up the gun just like it was before, went back outside, and the exact same thing happened. I think the shell jumped out of the gun somehow....I don't know

Now I'm really perplexed. I fill the mag up with some 180 grain federal hst.....go back out, and viola....no problem, no issue.

So....I'm completely lost and perplexed. I think the issue was with the ammo...I do have a stronger recoil spring.

The xdm appears fine, fires normal ammo ok. Next weekend I'm going to shoot it more to try to figure out what is going on.

Any ideas?


part two
figured it out
Shot a little today...shot some regular 40 cal hst....no problem, smooth as silk.

Put a few rounds of hot Swamp Fox in....same as before except this time instead of the live round flying out of the gun intact....a stove pipe occurred, with a live round.

I was almost happy to see this, but I had to test some more.

Put regular ammo back in, smooth as silk. Swamp Fox...stove pipe with a live round.

If Mike were still alive we'd be in touch. But....I'll just use my regular ammo in the 40 and be happy. The Swamp Fox 40 ammo is hereby quarantined. I have no desire to mess with it anymore. As of this moment, it ain't broke.

kaboom part
My right hand is wounded and I am shaking as I type. My wife and I got the crap scared out of us. I say my right hand is wounded....fingers intact, but I am bruised up pretty bad. Most of us think about high speed loads etc....every now and then a dose of reality sets in...let this be the dose for all of us, not just for me.

I have a lone wolf conversion 10mm to 40 cal barrel, and I knew the Swamp Fox 40 cal ammo was no threat to the almighty Glock 10 mm, so I go out to shoot some of it up, to use it up and just shoot some. I shoot two rounds, hit my target, and decide to do a double tap. I am not sure where in the next part the crap hits the fan, but I pull the trigger and the gun explodes in my hand. I run inside and make sure all my parts are still there, I have my wife check just to be sure as my heart is pounding 7000 beats a minute. I go back outside and find that the magazine has blown out of the gun, and a small plastic piece on the right side of the gun has blown out as well, adjacent to the mag(somebody tell me what this is cause I need a new one, no patience at the moment, more important to give out the warning), there is a spent shell in the barrel, and a live round pops out of the gun. I have to move the slide back and forth to get the empty out of the chamber.

The magazine with the live rounds is in the trash, there was some melting. The Swamp Fox 40 cal ammo is in the trash, a promise I made my wife. My wonderful Glock 29 has a hole in the right side and is out of commission.

I am at a loss for words. My hurt hand is nothing....I can't believe what just happened, and I can't believe that as bad as this could have been, that I able to type out this warning. I saw the Ravens fan thing about a bad attitude being the only true disability. Dang it, I am ok....I AM OK!!!!And I am so grateful, and make no apologies for my gratitude.

But I have to look out for you, because I don't have all the answers to what just happened. I only hope and pray that someone wiser than I can sort this out, so that we don't have to live this again.

Apologies for no pics...best descriptions at the moment...explosion blew the mag out of the bottom, Swamp Fox 40 cal ammo, melting of the mag at the top, small plastic piece blown out on the right side, otherwise gun appears intact.

G29 has 21 lb recoil spring

I am, at the moment, consuming a strong beer.

cause there for a moment, I thought I was really....


deadandgone



ed
 
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#127 ·
I am glad Glock worked with you to make your situation right at a reasonable price point!

I hear you about the weather, today is our first day without rain/hail in many days, colder dry air is expected for the next few days, that should dry things up a little!

Best regards!
 
#129 · (Edited)
I changed the heading on this topic...I believe the main factor here is the dangerous Swamp Fox ammo...of which I am sure there is more...if the consensus is that I should not do this, well feel free...I just don't think it was a Glock thing


Guess I can't do that...I changed the thread title, and a few minutes later it had reverted to the original title.....
 
#131 ·
I found out from Mike Cyrus(Lehigh Defense) who was talking to Kevin Underwood....Kevin seems to believe that Longshot can have pressure spikes in cold weather...kaboom happened in the winter with overloaded ammo.

Another piece of the puzzle. Now the above information may or may not be true, its just an observation from an ammo manufacturer. Worth thinking about.
 
G
#132 · (Edited)
Deadandgone, thanks for getting this back to page one. I am new to a G-29 and this forum had not read this thread yet. I got the Wolf 23# dual uncaptured spring and it has worked perfect from light to heavy loads. If I get a FTF in the future the first thing I will try is the stock 3 spring 17# RSA!

Does anyone have experience where a heavy load would do anything negative like "smile" or FTF with the stock RSA then work perfect with the heavier RSA using the same barrel factory or aftermarket?

Or has anyone worked up a hot load with the heavy RSA then put it into the stock RSA and experienced a problem?
 
#133 ·
It seems making your own ammo is the way to go. As long as you don't get distracted while reloading or ingest something sinful before hand, you would (or should) know what you get.
What happened here is why I load every one of my rounds. I drop with a PACT powder dispenser and beam scale the 1st 5 rounds. Every dimension is checked to insure there are within SAMMI spec. At the end of 50 rounds I weigh each loaded round to avoid squibs and over charges. I will not buy from boutique manufacturers. as this example proves their QC procedures are suspect. This is for both .40 and 10MM ammo I make. Every once fired case is down graded by .1 gr I always start with new starline cases CCI primers and use 155gr XTP, 165r Golden Saber or 165r Gold dots and load a little longer than spec by by .001 or .002
 
#134 · (Edited)
Happy you are okay, did you experience any trigger reset issues before the KB?

I posted this pic shortly after joining GT, this Winchester casing bulged so far that it couldn't be resized; it was practice ammo.



It was the last time I used a factory Glock barrel. I was rather Glock shy because it was about the same time a LEO had a G22 KB with department issued practice ammo.

I've used both KKM and Lonewolf barrels in two G20s without any issues. There are no reasons to buy "real" 10mm ammunition, JHP bullets lose penetration at uber velocities.

All the handloading manuals I have show downloaded powder data for unsupported 40S&W chambers.
 
#135 ·
The hotest factory load by a large manufacturer is the Hornady 165 gr critical defense 1175/506 for.40S&W. For the 10 mm it's the same bullet @ 1265/550 or the 180gr XTP 1180/556.
Book max for 155xtp with Longshot is 9.3 gr 1283 for th.40 I load mine at 8.8 1220ft/sec. I load 165gr Golden sabers or Speer Gold Dots with 10gr power pistol and get 1350f/sec w CCI 350 LPM can push to 1395/ 714 .Both bullets hold up well at that speed. No Glock smiles. Will only load that heavy with new cases.
 
#136 ·
If I understand correctly, an insufficiently-supported chamber won't necessarily damage the barrel as much as it will allow the explosive gases to explode through the back of the case doing pretty much what happened to you. Not blaming the barrel, but a fully supported chamber might provide better protection against this. But the main culprit may be super-hot loads that are not really thought through and tested properly.
I am happy that you are well.
I would put the rest of that SW ammo in the trash and try to live a long life.
This is why I use Barsto barrels. Never had a problem. My 2 OEM Glock barrels were not so good. They bulged cases with factory ammo.
 
#137 ·
Deadandgone, thanks for getting this back to page one. I am new to a G-29 and this forum had not read this thread yet. I got the Wolf 23# dual uncaptured spring and it has worked perfect from light to heavy loads. If I get a FTF in the future the first thing I will try is the stock 3 spring 17# RSA!

Does anyone have experience where a heavy load would do anything negative like "smile" or FTF with the stock RSA then work perfect with the heavier RSA using the same barrel factory or aftermarket?

Or has anyone worked up a hot load with the heavy RSA then put it into the stock RSA and experienced a problem?
I did some calculations a while back and convinced myself that the recoil spring has almost zero effect on when/where/how the barrel and slide unlock, regardless of the pressure of the load. It is entirely a function of slide mass, which explains why the G20 and G29 slides are so much heavier than Glock's similar models in other calibers. What the heavier spring weight does do, is to slow the slide velocity on the way back towards the shooter, and increase the slide velocity as it returns to battery. However, smiles are the result of pressure and barrel support, not "early unlocking" as some have theorized. An early unlocking of the slide and barrel would be catastrophic, which is why Glock pistols are designed in such a way that it can't happen (because of slide mass). You will blow up the barrel if you keep increasing chamber pressure, but the barrel will blow before the slide and barrel unlock, assuming the gun is fired fully in battery.

I'll also say that smiles in any barrel (Glock or AM) are over SAAMI pressure. I have fired all of my hot hand loads in the stock Glock barrels without any smiles. I know I'll stir up a lot of people here making these claims, but for your own safety, if you choose to shoot hot (nuke?) handloads (or boutique ammo), you should understand that things posted on the internet are not always safe and/or within the firearm manufacturer's design specification. Most guns can take a tremendous amount of overpressure without failing, but that's not what they were intended to do on a regular basis.

To answer your question, no, the spring weight will not make a difference if your ammo smiles the brass or not. It will only help to keep hot loads from battering your frame. That is really the only benefit of heavier springs. Most people, myself included, perceive slightly sharper recoil when using a heavier spring.
 
#138 ·
TDC, I think this is a pretty good take on lockup. It is apparent that there is likely a lot of validity to what you're saying. It is educational to remove the slide and to trace the forces that act on the slide by 1) the RSA, and 2) the lockup mechanism that is caused by the case pushing against the breach face while the bullet is simultaneously pushing the barrel forward into the slide. The RSA is acting against the frame to push the slide forward, and the barrel acting against the breach to push forward into the slide. Tough to explain on the phone, but a few minutes looking at the system will show what I'm talking about. I am not an engineer, so could easily be corrected.

I am not sure how much slide mass has to do with the system except to dampen the dynamics of the recoil event.

I have not tried this, but my hypothesis is that the slide would stay locked under bullet discharge even without an RSA. Of course one would need to find a way ensure that the gun started in battery before firing. Perhaps this could be done by securing the gun upside down and using a mechanism to remotely activate the trigger.
 
#139 · (Edited)
You're mostly correct, Taterhead. Actually, the barrel and slide are locked together, but not from the force of the case pressing against the breech face. The locking is done by the locking block forcing the barrel into the slide, which is held in position by the slide lugs in the frame. The top of the barrel, where it is squared off, is also held in place by the slide. The barrel and slide can move back about 0.080" before the locking block (or it could also be called the "unlocking block" ) forces the barrel down out of the slide, allowing the case to be pulled free from the barrel by the extractor. Most people don't realize that the slide and barrel are in motion before the bullet leaves the barrel, but they are.

I'm an engineer, but not a mechanical engineer. But back in my day, Universities required all Electrical, Mechanical, and Chemical Engineers to take a core curriculum including chemistry, physics, engineering mechanics (statics and dynamics), electrical circuits, and microprocessor programming. So, based on that, here is what I came up with, along with some factors which I know have an effect on the process, but which I considered small enough to be of little relevance...

With a loaded round and the pistol in full battery, the primer and powder is ignited, creating a rapid rise in pressure. The pressure in the chamber forces the bullet down the barrel with a force equal to pressure (in pounds per square inch, PSI) times the surface area of the bullet. As a locked system, the behavior initially is one where momentum is conserved, or M1*V1 = M2*V2, where M1 * V1 is the mass of the slide and barrel times the velocity of such, and M2 * V2 is the mass and velocity of the bullet and powder, which has been converted to gas. This is a simple calculation that most every shooting enthusiast has used to calculate recoil velocity.

If you measure the mass of the barrel and slide, and you know the velocity of the bullet (and powder, now converted to gas) leaving the barrel, you can calculate the slide/barrel velocity using the conservation of momentum equation. Now you can also calculate the acceleration of the slide using F = M*a. Since acceleration is a composite of the force from the bullet going one way, the force of the spring on the barrel and slide can be subtracted from the acceleration force. Spring tension is a function of Hooke's law, which means that the force increases as the spring is compressed more. Shadow has previously posted some great data on spring forces vs. where the slide position is. In battery, a 17lb Glock spring is something like 5 or 6 lbs, where a 22lb aftermarket spring is around 7-9 lbs. They are both close to their rating when fully compressed at the slide stop position. But even if you took the spring force to be 25 lbs in battery, it would have little relative effect.

Anyway, when you look at the force of the spring in battery, it is about 1/5000 (or less) of the effect of the barrel and slide mass acceleration force in retarding the slide movement. Keep in mind that the barrel can not unlock from the slide until that 0.080" of rearward movement occurs. Now, if you have all your calculations in a spreadsheet, you can vary the bullet velocity, thereby varying the slide/barrel velocity. What you will see is that, no matter how fast the bullet velocity is, the slide/barrel can not make the 0.080" movement to unlock before the bullet leaves the barrel. It's a very elegant and safe engineering solution to send a projectile at high velocity, using extremely high pressure gasses, with no danger to the shooter...ever. Even in extreme overloading, you can't unlock the system before the bullet leaves the barrel. I ran my calculations up to 100,000 PSI, and guess what? The bullet is out of the barrel before the slide and barrel unlock! (More realistically is that the barrel ruptures, but that will occur with the barrel and slide still locked up)

Some of the things that I simplified in my calculations are that I assumed linear acceleration of the bullet, which doesn't happen because the pressure curve that propels the bullet isn't a constant. Also, I did use a realistic mass for the powder (converted to gas), but only used a gas velocity equal to the bullet velocity, which I know is low. The gasses will exit the barrel faster than the bullet, but given the small mass, it turns out to be, not insignificant, but not dominant in the calculation, either. Friction in the gun system plays almost no part considering the forces at play during the dynamics of firing. I also only calculated to the point where the barrel begins to unlock from the slide, since that was the point of the whole exercise. Once the barrel unlocks, the exact dynamics of the system change, along with the effect of the recoil beginning to be transferred into the shooter's hand. This makes everything more difficult to model mathematically, but really at that point, what is a few fps in slide velocity? Maybe the difference in some frame battering.

But I agree, Taterhead. You could fire a Glock with no RSA installed, and there will be no catastrophic failure, only a very rough stop of the slide bashing into your frame.
 
#140 ·
Here are the measurements TDC20 was talking about for the Glock-20SF, this was with the non captive RSA from Wolff Gun Springs

Glock 20SF spring test Wolff Gun Springs 22lb RSA installed
It takes 6lb 4oz to start the slide to move from the locked position
Full retraction at 22lb 9oz at lock open

Glock 20SF spring test Wolff Gun Springs 24lb RSA installed
It takes 7lb 6oz to start the slide to move from the locked position
Full retraction at 24lb 1oz at lock open

Glock 20SF Factory spring test
It takes 5lb 3oz to start the slide to move from the locked position
Full retraction at 18lb 0oz at lock open

It doesn't take much pressure to keep a slide and barrel from unlocking either as you can place your thumb on the rear of the slide to keep it from moving...this was an interesting observation as well. An over sprung gun can change the cycling to the extent that it will not cycle correctly or at all.
 
#141 ·
This was my measurements for the G-29, this was with the non captive RSA from Wolff Gun Springs

Glock 29 spring test Wolff Gun Springs 21lb RSA installed
It takes 6lb 4oz to start the slide to move from the locked position
Full retraction at 21lb 3oz at lock open

Glock 29 spring test Wolff Gun Springs 23lb RSA installed
It takes 7lb 1oz to start the slide to move from the locked position
Full retraction at 23lb 5oz at lock open

Glock 29 Factory spring test
It takes 4lb 5oz to start the slide to move from the locked position
Full retraction at 16lb 10oz at lock open
 
#142 · (Edited)
TDC, I think this is a pretty good take on lockup. It is apparent that there is likely a lot of validity to what you're saying. It is educational to remove the slide and to trace the forces that act on the slide by 1) the RSA, and 2) the lockup mechanism that is caused by the case pushing against the breach face while the bullet is simultaneously pushing the barrel forward into the slide. The RSA is acting against the frame to push the slide forward, and the barrel acting against the breach to push forward into the slide. Tough to explain on the phone, but a few minutes looking at the system will show what I'm talking about. I am not an engineer, so could easily be corrected.

I am not sure how much slide mass has to do with the system except to dampen the dynamics of the recoil event.

I have not tried this, but my hypothesis is that the slide would stay locked under bullet discharge even without an RSA. Of course one would need to find a way ensure that the gun started in battery before firing. Perhaps this could be done by securing the gun upside down and using a mechanism to remotely activate the trigger.

I have personally seen a 1911 fired without a recoil spring. It functioned just like it normally would, only it didn't return to battery. I would imagine a Glock would function in a similar manner

[ame]http://youtu.be/Xyis5h9MvUU[/ame]
 
#143 ·
You're mostly correct, Taterhead. Actually, the barrel and slide are locked together, but not from the force of the case pressing against the breech face.

...
Great post. I did not quote all of it here for the sake of space. Thanks for taking the time to do the work, and for sharing it here.

Coincidentally, I started college as a mechanical engineering major before moving on to mathematics for a while. I ultimately finished with a couple of accounting degrees. Don't they say that people change majors on average a couple of times? I guess I was pretty typical in that respect. Ironically, I now work in the finance organization for a large engineering firm. So full circle? :dunno: That being said, I can't claim to be competent in engineering concepts. So you post was well-received.

Anyhow, back on track. My point about the breach face thingy was not to stipulate that it is what causes lockup. But I was hastily trying to illustrate that the mechanical systems of the RSA that causes the slide to return to battery are not the same systems that cause lockup. When I take my gun apart and trace the forces of the RSA, and then the mechanics of lockup, I can't see how the RSA has anything to do with lockup. You brought some formal mechanics to described what I've sort of thought all along. By the way, I'm the type of guy that would get geeky about your spreadsheet. :supergrin:
 
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