Tuner's Troubleshoot Time!

J

John Travis

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Lexington, NC or thereabouts.
Circa: 1995-ish

Subject: NIB Springfield Standard Mil-Spec

Issue: Empty case crushed horizontally between breechface and barrel hood.

Clues: Every time. Last round only. No matter the ammunition. No matter the magazine. No matter the grip force.
Extractor tension was good. Deflection was somewhat excessive, but not enough to cause feed/RTB problems...BUT...was related to the ejection issue. All other cases extracted and ejected cleanly, landing 6-8 feet from the gun on a slight rearward angle.

Gun was not easily repairable. Submitted to Geneseo warranty station with my notes and returned in working condition.

It's the little things that getcha.

Ready...Set...GO!
 
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Last round ejection is different, probably the same problem ejecting all rounds, but masked because the next round moving up was giving the case a boost.

You’d have fixed extractor deflection or clocking, so I’m guessing that the extractor tunnel was too far to the right and the factory tried to address it during assembly by applying excessive extractor tension. Fix would be a new slide.
 
JimB said:
Last round ejection is different, probably the same problem ejecting all rounds, but masked because the next round moving up was giving the case a boost.

You’d have fixed extractor deflection or clocking, so I’m guessing that the extractor tunnel was too far to the right and the factory tried to address it during assembly by applying excessive extractor tension. Fix would be a new slide.
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Very good, Jim!

The extractor was clocking and it was because the tunnel was too far to the right and angled, which caused the excessive deflection...which contributed to the issue in a strange way.

When a rim slipped up the breechface, it straightened the extractor up, masking the problem. Then, when the barrel dropped during linkdown and pulled the case down, the rim rotated the extractor counter clockwise and allowed the case to fall off the breechface. With no round under it, the extractor claw dragged the case partway back into the magazine before losing its grip...depressing the follower. Since the slide couldn't lock open, it ran forward and tried to feed the empty case and crushed it.

Because the extractor channel was mislocated, no oversized firing pin stop could stabilize it. The only cure was a new slide, which Springfield graciously provided. The gun was returned post-haste.

The really remarkable thing was how consistent the ejection was on all but the last round. In all other pistols I've seen with this particular glitch, ejection was all over the map.
 
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I can picture the extractor with my eyes open. When you start talking about problems caused by the fire control parts I close my eyes, drop my head, and eventually go look at the gif animation.
 
MacEntyre said:
Now, please tell us how you found and confirmed the answer back in '95,
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Oh, it goes back farther than that, though I'd never seen one clock quite that much before. Since the 90s, the only slides I've seen with the problem have been cast Essex/Thompson Auto Ordnance and Springfield. Essex is defunct and hopefully Springfield has corrected the problem.

Back to '95...

Looking at it until I nearly went blind, I noticed that the flat edge of the extractor was rotated instead of being vertical and just connected the dots.

Most extractors in ordnance-spec pistols will clock a little during normal use. As long as it's not an excessive amount, it never causes a problem other than slightly erratic ejection patterns. Part of that is caused by varying degrees of excessive deflection, which is what ultimately led me to make adjustments for it as part of a tuneup. When EGW started offering oversized firing pin stops, I could completely stabilize the extractor without having to make them from barstock...which I'd been doing for a number of years after discovering what the small firing pin stop radius effect was.
 
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right/left doesn’t get me there… was it toward or away from the center of the gun?
 
John Travis said:
View attachment 465128
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Just picked this one up (Colt Mk IV Gvmt series 70) and had some weirdness at the range that made me think of this thread. Extractor tension is good but it occasionally holds onto a case and crushes it as described above. Lo, and behold, look at the extractor:

20220506_100144.jpg
 
I don't think it's an offset channel but it is clocking, which brought me back here to review your notes.

20220506_132917(1).jpg
 
John Travis said:
And there it is. The channel is mislocated. Not much you can do with it. Sorry to be the bearer of bad tidings. Colt's early Series 70 days were hit and miss as far as QA went.
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Don’t you think that the issue could be minimized, if not eliminated, with a better fitting slide stop? Seems both narrow and over beveled.

Cheap to try.
 
If I can find an oversized stop in stock I'm gonna throw $20 at it and see what happens.
 
Catfish said:
If I can find an oversized stop in stock I'm gonna throw $20 at it and see what happens.
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I would, even if the odds are low. The rotation is prevented by the side of the FPS fitting into the groove cut in the extractor. I wonder if there are extractors with oversized grooves available.

Of course sending pics and describing the problem to Colt might get you a better solution, that’s also worth a try.
 
Catfish said:
If I can find an oversized stop in stock I'm gonna throw $20 at it and see what happens.
Click to expand...

Catfish said:
Ya really believe I've never tried that?

That channel is a good sixteenth inch too far to the right. Installing a firing pin stop that might place the right edge .003 inch closer to the floor of the slot in the extractor won't make a whit of difference.
You have a small chance of moderating the last round crunch and bringing it down to a more tolerable level.
Because the channel is very likely angled, the tensioning wall is protruding too far into the breech area. When the rim of the case hits that protrusion as it slides up the breechface, it rotates the extractor counter clockwise. By reducing that protrusion to a minimum, you can reduce the effect that the case rim has on rotating the extractor. Then, increase the bend in the extractor to effect a tighter fit in the channel, and you can alleviate it quite a bit. I've had limited success with this method, and I've never been able to stop it completely...but on a range-only pistol...it's liveable. I wouldn't trust it for a carry gun.

The sticky part is that without the right tools and the know-how, you can trash your extractor in quick time. .
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Post this photo of your slide.
This is a Springfield slide that produced the same malfunction as you described as well as intermittent failure to go to/return to battery. The channel was angled out at the rear...in at the front. You can see where the owner tried to address the problem by rounding the lower edge of the tensioning wall...to no avail.


ZDeflection_zps7ba1f5b6.jpg
 
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RetiredUSNChief said:
The heck we don't!

Except "Red, right, returning".
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board the Tug Whitefoot, we useta meet nuclear attack subs(never the boomers) halfway to Bermuda to run sonar calibrations with a special noise maker we lowered into the water. They would send one crewman with us to make the rendevous on a classified chart that we kept in the bottom of the chart drawer. He's the one that tol' us they use Right and Left, instead of Starboard and Port. He also tol' us they couldn't go very fast, but we didn't believe that...
 
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MacEntyre said:
board the Tug Whitefoot, we useta meet nuclear attack subs(never the boomers) halfway to Bermuda to run sonar calibrations with a special noise maker we lowered into the water. They would send one crewman with us to make the rendevous on a classified chart that we kept in the bottom of the chart drawer. He's the one that tol' us they use Right and Left, instead of Starboard and Port. He also tol' us they couldn't go very fast, but we didn't believe that...
Click to expand...

If a submariner tells you something, anything, it's likely at least 75% lies.
 
MacEntyre said:
board the Tug Whitefoot, we useta meet nuclear attack subs(never the boomers) halfway to Bermuda to run sonar calibrations with a special noise maker we lowered into the water. They would send one crewman with us to make the rendevous on a classified chart that we kept in the bottom of the chart drawer. He's the one that tol' us they use Right and Left, instead of Starboard and Port. He also tol' us they couldn't go very fast, but we didn't believe that...
Click to expand...

Yeah, well, he was a Sonar Tech. What can I say? You need an "S" and a "T" to spell "stupid".
 
John Travis said:
Post this photo of your slide.
This is a Springfield slide that produced the same malfunction as you described as well as intermittent failure to go to/return to battery. The channel was angled out at the rear...in at the front. You can see where the owner tried to address the problem by rounding the lower edge of the tensioning wall...to no avail.
Click to expand...
Here are a couple shots of that area. Did I catch the right angle?

20220508_133646.jpg

20220508_133653.jpg
 
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