My Glock 22 blew up in my hand today

[dcmdon]

Re heavy vs light.

There has kindof become a bit of a misunderstanding re light vs heavy bullets as a result of people trying to make IPSC major power factor.

When trying to make power factor, many people have found that the slower recoil of a heavier bullet is preferable.

Unfortunately the internets has taken that to mean taht all heavy loads for a given caliber are lighter recoiling. That is simply not true. My 124 gr 9mm loads recoil appreciably less than my 147s. The 124s have a lower power factor. And if I tried to get the 124s up to the same power factor, they may recoil more than the 147s.

But I don't shoot IPSC. All I care is that they cycle the gun reliably. And if that is my goal, I've found I can get a lighter recoiling load with lighter bullets.

As a point of reference my loads are:

147 gr precision bullet truncated cone coated, 5.0 gr of AA5
124 gr precision delta fmj or hp, 5.6 (ish I don't have my diary in front of me) of AA5

Don

 

[bigblue]

Re heavy vs light.

There has kindof become a bit of a misunderstanding re light vs heavy bullets as a result of people trying to make IPSC major power factor.

When trying to make power factor, many people have found that the slower recoil of a heavier bullet is preferable.

Unfortunately the internets has taken that to mean taht all heavy loads for a given caliber are lighter recoiling. That is simply not true. My 124 gr 9mm loads recoil appreciably less than my 147s. The 124s have a lower power factor. And if I tried to get the 124s up to the same power factor, they may recoil more than the 147s.

But I don't shoot IPSC. All I care is that they cycle the gun reliably. And if that is my goal, I've found I can get a lighter recoiling load with lighter bullets.

As a point of reference my loads are:

147 gr precision bullet truncated cone coated, 5.0 gr of AA5
124 gr precision delta fmj or hp, 5.6 (ish I don't have my diary in front of me) of AA5

Don

"Perceived recoil"
Heavier bullet weights generally have less perceived recoil simply because there is less powder exploding in the case which sends the bullet at a slower velocity. When you have two otherwise equivalent loads, the one with less of the same powder and a slower bullet should have less felt recoil.
Chamber pressure < > felt recoil; there are many other factors like powder burn rate, barrel length, and bullet weight.
I have yet to see an effective comparison of bullets & powders graphed against felt recoil. I wonder if you could do a similar comparison as to the AR comp & brake tests?

 

[180 GRAIN FMJ]

Does anyone know if they tightened up the chamber in the 4th gen 40's or is it still a sloppy disaster waiting to happen?

 

[drgrant]

Does anyone know if they tightened up the chamber in the 4th gen 40's or is it still a sloppy disaster waiting to happen?

Why would the design change? Its not the "slop" thats the problem, it's the fact that .40 sucks and theres only minimal support at 6oclock. To be honest though that still wouldn't stop me from buying one. Even given the obvious preference for .40 KBs, your odds of having a gun blow up are pretty small to the point it's almost meaningless. I owned a G22 Gen4 for a couple months then sold it. During that time it worked well. If I had a use for .40, I'd buy another.

 

[jraysig]

I spoke with Glock today. They're blaming the ammunition. I've got a call into them to see how to go about getting it warrantied. Thank you everyone for the help! Much appreciated.

 

[beaker]

Does anyone know if they tightened up the chamber in the 4th gen 40's or is it still a sloppy disaster waiting to happen?

Why do you think that Glock chamber design is a disaster waiting to happen?

 

[dcmdon]

"Perceived recoil"
Heavier bullet weights generally have less perceived recoil simply because there is less powder exploding in the case which sends the bullet at a slower velocity. When you have two otherwise equivalent loads, the one with less of the same powder and a slower bullet should have less felt recoil.
Chamber pressure < > felt recoil; there are many other factors like powder burn rate, barrel length, and bullet weight.
I have yet to see an effective comparison of bullets & powders graphed against felt recoil. I wonder if you could do a similar comparison as to the AR comp & brake tests?

Yes, but momentum, which is what generates recoil is a linear function. momentum = Mass x Velocity Which is the same as power factor. Which is just momentum divided by a constant of 1000.

Conversely, muzzle energy is a square function. Energy= ((MxV)^2)/2

So what it comes down to is that for a given energy, a lighter bullet has a lower velocity.

And for a given momentum or Power Factor, a heavier bullet has less kinetic energy.

So it all comes down to what I said before. If your goal is to make a power factor, heavier bullets almost always have less perceived recoil.
But if your goal is not to make power factor, but just to cycle the gun, its up in the air.

Don

 

[180 GRAIN FMJ]

Why do you think that Glock chamber design is a disaster waiting to happen?

Because 90% of the KB's seem to happen in 2nd and 3rd gen Glock 40's. The chambers have long been criticized as being too loose.

Why would the design change?

Looks like they did quietly tighten them up:

 

[Sinitron]

Because 90% of the KB's seem to happen in 2nd and 3rd gen Glock 40's. The chambers have long been criticized as being too loose.



Looks like they did quietly tighten them up:

View attachment 149613

Wow that picture is interesting, really shows the differences.

 

[Da_lucche]

You weren't using Freedom Munitions, were you?

 

[M1911]

You weren't using Freedom Munitions, were you?

Fiocchi: http://www.northeastshooters.com/vb...y-hand-today?p=4712235&viewfull=1#post4712235

 

[beaker]

Interesting. I don't do 40 and wasn't aware that this was an issue with 40 glocks.

Because 90% of the KB's seem to happen in 2nd and 3rd gen Glock 40's. The chambers have long been criticized as being too loose.



Looks like they did quietly tighten them up:

View attachment 149613

Sent from my SM-G920V using Tapatalk

 

[AHM]

Yes, but momentum, which is what generates recoil is a linear function. momentum = Mass x Velocity Which is the same as power factor. Which is just momentum divided by a constant of 1000.

Conversely, muzzle energy is a square function. Energy= ((MxV)^2)/2

So what it comes down to is that for a given energy, a lighter bullet has a lower velocity. ...

What are you actually trying to say here?
Because E=½mv² implies the opposite conclusion.

Marry any given lead bullet with a certain seating depth and powder charge and type.
Measure its muzzle velocity.

Replace the lead bullet with aluminum of the same size and shape.
As long as the energy imparted by burning powder is the same,
it's not going to have a lower muzzle velocity.

Replace the lead bullet with depleted uranium of the same size and shape.
As long as the energy imparted by burning powder is the same,
it's not going to have a higher muzzle velocity.

Are there unstated assumptions about seating depths, or pressure curves attained when pushing against heavier or lighter projectiles? I'm sure I can't speak to such factors.

Thanks in advance.

 

[dcmdon]

AHM.

Replace the lead bullet with aluminum and it will go faster with similar energy.

But it will have much less momentum, which is a linear function.

Conversely, put in a depleted Uranium bullet and it will go slower, with similar energy.
But its momentum will be higher

Recoil is a function of bullet momentum, not energy

M*V(gun) = M*(-V)(bullet) (negative indicating that the v is in the opposite direction)

Mass of both items is known.
Velocity of the bullet is known
Solve for the velocity of the firearm (called free recoil velocity) and that is a reasonable measure of recoil.

On a practical level, the .300 blk is a round that works very well to demonstrate this because of the huge difference in bullet weight loadings available.

I need to make up some demonstration loads using the same amount of the same powder, except one using a 230 gr bullet and the other using a 110 gr bullet.

Don

 

[AHM]

Replace the lead bullet with aluminum and it will go faster with similar energy.

An example worked with lead and aluminum:

Lead weighs 11.36 gm/cm³; aluminum weighs 2.70 gm/cm³. The mass ratio (which is all we care about) is that an identically sized aluminum bullet will be 4.21 times as light as the lead bullet.

If the same charge results in basically the same transfer of K.E. to the two bullets, then the aluminum bullet's muzzle velocity will be the square root of the mass ratio. Since SQRT(4.21) == 2.05, the aluminum's muzzle velocity will be about twice as fast as the lead bullet's.

But it will have much less momentum, which is a linear function.

The aluminum bullet will weigh 1/4.21 as much, but will be going 2.05 times as fast, so will have 2.05/4.21 == 1/2.05 == 0.49 times the momentum of the lead bullet. (That factor is the inverse of the square root of the mass ratio).

... I need to make up some demonstration loads using the same amount of the same powder, except one using a 230 gr bullet and the other using a 110 gr bullet.

The chrono results would be interesting.

 

[bill o]

AHM.
I need to make up some demonstration loads using the same amount of the same powder, except one using a 230 gr bullet and the other using a 110 gr bullet.

Don

Some Single Stack competitors use the same powder charge with a 180 grain bullet for major, 155 for minor. The major load has a lot more recoil of course.

 

[strangenh]

I spoke with Glock today. They're blaming the ammunition. I've got a call into them to see how to go about getting it warrantied. Thank you everyone for the help! Much appreciated.

Did you speak with Fiocchi? (Or is Glock going to do that?)

 

[dcmdon]

An example worked with lead and aluminum:

Lead weighs 11.36 gm/cm³; aluminum weighs 2.70 gm/cm³. The mass ratio (which is all we care about) is that an identically sized aluminum bullet will be 4.21 times as light as the lead bullet.

If the same charge results in basically the same transfer of K.E. to the two bullets, then the aluminum bullet's muzzle velocity will be the square root of the mass ratio. Since SQRT(4.21) == 2.05, the aluminum's muzzle velocity will be about twice as fast as the lead bullet's.


The aluminum bullet will weigh 1/4.21 as much, but will be going 2.05 times as fast, so will have 2.05/4.21 == 1/2.05 == 0.49 times the momentum of the lead bullet. (That factor is the inverse of the square root of the mass ratio).



The chrono results would be interesting.

Isn't physics great. Thanks for doing the math.

A couple of other things that are beyond my ability to adjust for.

1) how does friction in the barrel change as speed increases? Is it linear? Or does the fact that a faster moving bullet will get hotter faster, decrease the rate of increase of friction?

2) The lead bullet will accelerate more slowly. Allowing for a higher average pressure during its trip down the barrel. This will increase the efficiency of the charge. (more of the chemical energy is actually put to use being converted to kinetic energy). How much of a difference will this make.

3) one assumption is we would ignore any frictional differences between lead and aluminum. i.e. Assume the chicken is spherical.

 

[jraysig]

At the end of the day I'm having it rebuilt by a Glock armorer. The person who sold me the ammo is having it fixed for a hundred dollars. All new Glock parts. Much easier than going back and fourth with Glock and the ammo manufacturer. In theory it should be good as new. I will say from here on I'm sticking with a 9 or a 45ACP

 

[bigblue]

At the end of the day I'm having it rebuilt by a Glock armorer. The person who sold me the ammo is having it fixed for a hundred dollars. All new Glock parts. Much easier than going back and fourth with Glock and the ammo manufacturer. In theory it should be good as new. I will say from here on I'm sticking with a 9 or a 45ACP

I have had two dealings with gun & ammo mfg's related to failures and case ruptures. Both times the ammo mfg took care of the whole situation no questions asked. I simply provided pics and a list of damaged parts then they mailed me a check. The rifle was a $750 check so it wasn't pocket change.

Glad the FFL is covering the repairs but it's not really his fault or responsibility: He is just being nice to keep your business. The mfg should be footing the bill not an independent businessman.

 

[dcmdon]

I've been following the thread from teh beginning.

Did the OP ever go to the ammo manufacturer?

 

[jraysig]

I called and left a message. After hearing from the dealer who said they'd repair it I didn't call back. Gun should be ready for pick up early this week.

 

[AHM]

Isn't physics great. Thanks for doing the math.

No sweat. I've been interested in kinetics for a very long time, but I didn't have a feel for this niche. So I wanted to work it out.

A couple of other things that are beyond my ability to adjust for.

1) how does friction in the barrel change as speed increases? Is it linear? Or does the fact that a faster moving bullet will get hotter faster, decrease the rate of increase of friction?

The math for the first-level approximation of [dry] friction is very simple, and normally it goes a long way. But for all I know the conditions inside a barrel (particularly including temperature and speed) get outside the envelope where the approximation applies.

2) The lead bullet will accelerate more slowly. Allowing for a higher average pressure during its trip down the barrel. This will increase the efficiency of the charge. (more of the chemical energy is actually put to use being converted to kinetic energy). How much of a difference will this make.

I absolutely agree it's a big "if", and it may be too big to ignore. Also, solid rocket fuels' burn rates can be a very funky function of pressure. Many here might know exactly how smokeless and black powder are modeled (I don't), but I won't be surprised if they're funky enough for it to matter.

3) one assumption is we would ignore any frictional differences between lead and aluminum. i.e. Assume the chicken is spherical.

I assume that the two coefficients of friction are different for lead/steel vs. aluminum/steel. Whether the effect on projectile performance is significant, I can't guess.

One could eliminate that factor by using plating or jackets (or maybe lube). At least the math for lube is probably so difficult it eliminates the temptation to try.

 

[jraysig]

I got the gun back. It's good as new!!!!!!!!!!!!!!!!!!! Thank you all for your help.

 

[fencer]

I got the gun back. It's good as new!!!!!!!!!!!!!!!!!!! Thank you all for your help.

Damn. That was quick! Whole bunch of awesome there.

 

[dcmdon]

Glock got my G42 (that I screwed up) back to me in 10 days. they paid for shipping both ways. You don't hear about Glocks great service very often because most people never need it. I've probably got 100,000 rounds through all my glocks in total and have never had an issue that had anything to do with the gun itself.