Overpressure?

Poodleshooter · September 23, 2002, 11:18 AM

I've had some trouble with a recent .45ACP loading of 4grs of Clays under a 230gr LRN moving at just around 800fps. Periodically during a recent IDPA match, after about 40-50 rounds had been fired, my Glock's extractor would slip over the round, leaving it partially extracted and hanging halfway out of the chamber, causing a slide stoppage. There are no unusual marks on the case from the extractor claw. The barrel is, of course, fully crudded up with lead, though that usually isn't a problem for less than 100 rounds. On visual inspection, the extractor is ok, and the pistol functions well with other reloads.
I had tested 25 of these rounds the previous day with no problems, though during extensive 1-200 round tests earlier in the week I had experienced soft primer strikes in about 10% of the cartridges. These left a shallow dent, but fired on restrikes. Those rounds left me wondering if the pistol was locking up properly, but visual inspection showed that the slide was locked up properly for each shot. The bullets may have been seated a bit too far out in that case, as I was still toying with pressure. When seated deeper and crimped tighter in the subsequent batch, the soft strikes disappeared, but this extraction issue cropped up!
So any ideas on what is to blame on the newest batch? Sticky case from overpressure? Excessive slide speed slipping the extractor over the case?

**Mike Irwin** · September 23, 2002, 12:03 PM

Sounds like a bad or dirty extractor or spring. Try pulling the extractor and cleaning the hook thoroughly.

Poodleshooter · September 23, 2002, 07:00 PM

I never have pulled the extractor on my Glock. I usually just spray under it with brake cleaner. Still, it seems odd that it would just start malfunctioning with this ammo, function fine with other ammo, then malfunction again with the original ammo. Ah well, probably a good time to get an aftermarket barrel to eliminate all of that lead fouling.

WESHOOT2 · September 23, 2002, 08:13 PM

But I suspect the ammo.

In a dirty gun.

Suggest changing one thing at a time; start with barrel-only cleaning.

Poodleshooter · September 23, 2002, 09:37 PM

The barrel was filthy for each set of malfunctions, however the fouling was in the throat (the Glock/lead thing),not the chamber or the lockup area. Several rounds were test fit into the barrel after the first malfunctions. Some dropped in easily, a few seated properly with very slight finger pressure, and dropped in subsequently. I couldn't draw a correlation between case fit and malfunctions.
I have checked the extractor. It's quite clean, even underneath, and moves freely. I just don't understand why it would slip over a few rounds, then function fine for awhile, then slip over another few. The charges were uniform, as I tested a batch of 25, done at the same time, for velocity consistency. Extreme spreads were only running around 20fps.
What makes an extractor fail to fully extract, besides extractor failure?
This is treading the line of several different forums, but I'm inclined to blame the ammo, hence the threads residence here.
Perversely, I'm tempted to run up about 200 rounds of this load and try to duplicate the failures.....

stans · September 24, 2002, 05:53 AM

I don't have a Glock, but I have read that they do not perform well with lead bullets. Might I suggest you try jacketed or plated bullets with a clean barrel and see if the problem dissappears.

September 23, 2002, 11:18 AM	#1
Poodleshooter Senior Member Join Date: August 7, 2000 Location: Floating down the James River in VA Posts: 2,599	Overpressure? I've had some trouble with a recent .45ACP loading of 4grs of Clays under a 230gr LRN moving at just around 800fps. Periodically during a recent IDPA match, after about 40-50 rounds had been fired, my Glock's extractor would slip over the round, leaving it partially extracted and hanging halfway out of the chamber, causing a slide stoppage. There are no unusual marks on the case from the extractor claw. The barrel is, of course, fully crudded up with lead, though that usually isn't a problem for less than 100 rounds. On visual inspection, the extractor is ok, and the pistol functions well with other reloads. I had tested 25 of these rounds the previous day with no problems, though during extensive 1-200 round tests earlier in the week I had experienced soft primer strikes in about 10% of the cartridges. These left a shallow dent, but fired on restrikes. Those rounds left me wondering if the pistol was locking up properly, but visual inspection showed that the slide was locked up properly for each shot. The bullets may have been seated a bit too far out in that case, as I was still toying with pressure. When seated deeper and crimped tighter in the subsequent batch, the soft strikes disappeared, but this extraction issue cropped up! So any ideas on what is to blame on the newest batch? Sticky case from overpressure? Excessive slide speed slipping the extractor over the case?

September 23, 2002, 12:03 PM	#2
Mike Irwin Staff Join Date: April 13, 2000 Location: Northern Virginia Posts: 41,380	Sounds like a bad or dirty extractor or spring. Try pulling the extractor and cleaning the hook thoroughly. __________________ "The gift which I am sending you is called a dog, and is in fact the most precious and valuable possession of mankind" -Theodorus Gaza Baby Jesus cries when the fat redneck doesn't have military-grade firepower.

September 23, 2002, 08:13 PM	#4
WESHOOT2 Senior Member Join Date: February 20, 1999 Location: home on the range; Vermont (Caspian country) Posts: 14,324	YOU CAN BLAME THE GUN But I suspect the ammo. In a dirty gun. Suggest changing one thing at a time; start with barrel-only cleaning. __________________ . "all my ammo is mostly retired factory ammo"

September 23, 2002, 07:00 PM	#3
Poodleshooter Senior Member Join Date: August 7, 2000 Location: Floating down the James River in VA Posts: 2,599	I never have pulled the extractor on my Glock. I usually just spray under it with brake cleaner. Still, it seems odd that it would just start malfunctioning with this ammo, function fine with other ammo, then malfunction again with the original ammo. Ah well, probably a good time to get an aftermarket barrel to eliminate all of that lead fouling.

September 23, 2002, 09:37 PM	#5
Poodleshooter Senior Member Join Date: August 7, 2000 Location: Floating down the James River in VA Posts: 2,599	The barrel was filthy for each set of malfunctions, however the fouling was in the throat (the Glock/lead thing),not the chamber or the lockup area. Several rounds were test fit into the barrel after the first malfunctions. Some dropped in easily, a few seated properly with very slight finger pressure, and dropped in subsequently. I couldn't draw a correlation between case fit and malfunctions. I have checked the extractor. It's quite clean, even underneath, and moves freely. I just don't understand why it would slip over a few rounds, then function fine for awhile, then slip over another few. The charges were uniform, as I tested a batch of 25, done at the same time, for velocity consistency. Extreme spreads were only running around 20fps. What makes an extractor fail to fully extract, besides extractor failure? This is treading the line of several different forums, but I'm inclined to blame the ammo, hence the threads residence here. Perversely, I'm tempted to run up about 200 rounds of this load and try to duplicate the failures.....

September 24, 2002, 05:53 AM	#6
stans Senior Member Join Date: November 9, 2001 Location: Virginia, USA Posts: 838	I don't have a Glock, but I have read that they do not perform well with lead bullets. Might I suggest you try jacketed or plated bullets with a clean barrel and see if the problem dissappears.