Need a diagnosis - Page 2

Foxbat · October 28, 2009, 12:04 PM

Speaking of "unsupported" chambers, here are three shells - the one on the left was fired from SW99 pistol. The two others show by way of a scratch, how much of the case is exposed.

The middle picture is the SW99. Note that the resulting bulge is actually larger than the scratch area - possibly indicating early breach opening.

The case on the right is from Glock 23.

Foxbat · October 28, 2009, 12:07 PM

"Foxbat,

Is it possible that the Winchester cases were previously fired in a glock, perhaps even with excessive charges, before they were reloaded and fired again to create the blown-cases? Or, did they blow when they were fired as WW Whitebox loads?

SL1 "

No, they were fired once prior to that. I never had any problems shooting the original WB, regardless of the pistol. The WB load is fairly mild, and cases usually show no signs of any overpressure.

Sarge · October 28, 2009, 12:26 PM

'Chamber support' is not necessarily a constant and is relevant as it relates to specific handguns. The following is posted for reference only.

Farmland · October 28, 2009, 01:20 PM

Here is the photo of the over loaded 40 S & W round that blew in my Beretta. It was operator error and confirmed after pulling the bullets. All 50 rounds were over loaded. I had made a mistake with my scale readings.

The case was never fired through a Glock.

Farmland · October 28, 2009, 01:22 PM

For the full story on my case you can read this thread.

http://www.thefiringline.com/forums/...d.php?t=367060

Scorch · October 28, 2009, 01:59 PM

As others have said, it looks like the case heads were unsupported during firing, causing the ruptures seen. But the cause of the rupture is not just because of the unsupported case head, it looks like the gun was opening under pressure, which you could get if the ammo was loaded with fairly slow powder. Look at the primer in the third picture: it looks like the gun was opening under pressure, which would cause the blown head issues seen in the other three cases also.

The fourth case is simply fatigued brass. Like any metal, brass fatigues when it is worked too much, then it cracks. It happens sometime between the 1st firing and the 101st firing. Happens in all brass cases sooner or later, no matter if they are 9mms, 38s, 357s, 40s, 44s, 45s.

PCJim · October 28, 2009, 05:41 PM

I'm tending to follow Scorch on this one. The cases were definitely without support (pics 1-3), possibly/probably due to the slide not being fully closed. I'd check the gun to see if it will fire with partially open slide. Also check OAL of the reloads to see if excessive OAL could have prevented the slide from closing?

October 28, 2009, 12:26 PM	#28
Sarge Senior Member Join Date: May 12, 2002 Location: MO Posts: 5,457	'Chamber support' is not necessarily a constant and is relevant as it relates to specific handguns. The following is posted for reference only. __________________ People were smarter before the Internet, or imbeciles were harder to notice.

October 28, 2009, 01:59 PM	#31
Scorch Senior Member Join Date: February 13, 2006 Location: Washington state Posts: 15,248	As others have said, it looks like the case heads were unsupported during firing, causing the ruptures seen. But the cause of the rupture is not just because of the unsupported case head, it looks like the gun was opening under pressure, which you could get if the ammo was loaded with fairly slow powder. Look at the primer in the third picture: it looks like the gun was opening under pressure, which would cause the blown head issues seen in the other three cases also. The fourth case is simply fatigued brass. Like any metal, brass fatigues when it is worked too much, then it cracks. It happens sometime between the 1st firing and the 101st firing. Happens in all brass cases sooner or later, no matter if they are 9mms, 38s, 357s, 40s, 44s, 45s. __________________ Never try to educate someone who resists knowledge at all costs. But what do I know? Summit Arms Services

October 28, 2009, 12:04 PM	#26
Foxbat Senior Member Join Date: January 13, 2008 Posts: 367	Speaking of "unsupported" chambers, here are three shells - the one on the left was fired from SW99 pistol. The two others show by way of a scratch, how much of the case is exposed. The middle picture is the SW99. Note that the resulting bulge is actually larger than the scratch area - possibly indicating early breach opening. The case on the right is from Glock 23.

October 28, 2009, 12:07 PM	#27
Foxbat Senior Member Join Date: January 13, 2008 Posts: 367	"Foxbat, Is it possible that the Winchester cases were previously fired in a glock, perhaps even with excessive charges, before they were reloaded and fired again to create the blown-cases? Or, did they blow when they were fired as WW Whitebox loads? SL1 " No, they were fired once prior to that. I never had any problems shooting the original WB, regardless of the pistol. The WB load is fairly mild, and cases usually show no signs of any overpressure.

October 28, 2009, 01:20 PM	#29
Farmland Senior Member Join Date: July 5, 2009 Posts: 869	Here is the photo of the over loaded 40 S & W round that blew in my Beretta. It was operator error and confirmed after pulling the bullets. All 50 rounds were over loaded. I had made a mistake with my scale readings. The case was never fired through a Glock.

October 28, 2009, 01:22 PM	#30
Farmland Senior Member Join Date: July 5, 2009 Posts: 869	For the full story on my case you can read this thread. http://www.thefiringline.com/forums/...d.php?t=367060

October 28, 2009, 05:41 PM	#32
PCJim Senior Member Join Date: July 11, 2008 Location: FL Posts: 570	I'm tending to follow Scorch on this one. The cases were definitely without support (pics 1-3), possibly/probably due to the slide not being fully closed. I'd check the gun to see if it will fire with partially open slide. Also check OAL of the reloads to see if excessive OAL could have prevented the slide from closing?