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Case Failure



 Cartridge Case Failures



Revised 2011-09-01
Revised 2014-11-18

Handgun Case Failures

This is the most common form of handgun case failure. The lengthwise split. about 75% of the start at the case mouth and run backwards but a few start in the center of the case body. 

These failures are not dangerous and in most cases, you will not know it occurred until you eject the cases from the cylinder. The bullet will not even go astray.

See the next panel.

Case Failure

This is the same case as above lying on the target I was shooting at when the split occurred. Can you guess which one of those holes was created by the failed case?

I am pretty sure you can't. It was the middle hole of the string of three running upwards from 12 O'clock.

Load:
Mixed old .38 special commercial.
4.2 gr Accurate No. 2
CCI SP Primer
Lee 358 158 SWC
Tumbled with LLA.
Range 50 yards

The black square is exactly 1" wide outside to outside.

Case Failure

Two more exampled of split cases. Both .38 special.

Most of my split cases are .38 special because something north of 90% of my shooting is done with that cartridge. And because I can't keep up with .45s and 9mms long enough to wear them out.

   

.44 Magnum

 

This was a full bore .44 Magnum reload.
20 Grains 2400 with a 250 Grain Keith bullet.

Fired in a .45 Colt Cylinder in a .44 Magnum Ruger Blackhawk.
The gun was bought at a gun show and looked pristine.
It was- except somebody swapped the cylinder.



Cartridge Case Failure
Same failure as above except this case split and the case above did not.
You do not see the bulge because the split is straight along the bulge and is facing up in this photo.

This was a full bore .44 Magnum reload.
20 Grains 2400 with a 250 Grain Keith bullet.
Cartridge Case Failure
   

This is a .45 ACP aluminum case. It is a factory original load. This is a relatively dangerous case failure. It definitely leaked gas back into and out of the action.

Since the handgun was a couple of feet in front of the shooters face, he probably was not aware of the failure. If this had been a rifle round fired in a bolt action with the back of the action near the shooter's face, he would almost certainly felt the escaping gas on his skin and probably a few black spots on his glasses.

Be sure to expand this photo and notice the following:

  1. Gas leakage back past the rim of the cartridge into the action - outside the chamber.
  2. More gas leakage into the extraction groove.
  3. The bright ring is the obturation* ring. The walls of the cartridge case are designed to expand and obturate ( block ) the backward flow of high pressure gases into the action of the firearm. Behind this ring the metal of the cartridge body is to thick to be expanded by the chamber pressure.
  4. Bright scratches caused by the wall of the case "sticking to" the chamber and being scratched as the extractor pulls it out of the chamber.

* This ring is not usually visible and is usually considered a reliable sign of high pressure. High pressure is a relative term, meaning higher than the cartridge case was designed to contain.

45 ACP case failure at base,

   
   

Rifle Case Failures

 

.270 Winchester Case Failure (1)

 
This is a .270 Winchester factory load.

This is a very dangerous failure because it occurs behind the main body of the case in the area where the case cannot expand to obturate the flow of the gasses. Note that the gas has found its way into the extractor groove.

Notice that the gas residue expands outward from the split around the circumference of the case but does not expand forward. In fact there is a straight line at which the gas expansion stops. This is the point at which the case has expanded against the chamber walls sealing off the flow of the gas.  This sealing is called obturation.
Rifle Case Failure
Close up of the same case, again note the gas  in the extractor groove. Rifle Case Failure
Extreme close up after cleaning away the carbon. Rifle Case Failure
Same case from the inside. ( after cleaning. ) Rifle Case Failure

.270 Winchester Case Failure (2)

 
   
.270 Winchester P-P head stamp
Factory load
NO primer indication of high pressure.
Rifle Case Fail
Same case as above. Note that the primer looks normal. Rifle Case Failure
   
   

.30-30 Winchester Case Failure

 
   
   
This is .30-30 Winchester reload failure
Case is W-W twice fired. ( First reload )
Load was Lee 309-170-F
Sized .311
25.0* GR Accurate 2015
Velocity Est 1900
Firearm TC G2.

Western lists 27 grains as Max.
My opinion is that 25 is already too hot.
See the next example.

Rifle Case Failure
This is .30-30 Winchester reload failure
Case is W-W twice fired. ( First reload )
Same case as above.
Close up of split shoulder.
Rifle Case Failure
This is .30-30 Winchester reload failure
Case is W-W twice fired. ( First reload )
(This is not the same case as above )
Load was Lee 309-170-F
Sized .311
25.0* GR Accurate 2015
Velocity Est 1900
Firearm TC G2.

Western lists 27 grains as Max.
My opinion is that 25 is already too hot.


  
Rifle Case Failure

 

 

 
 

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