What caused this FTE?

[Skribs]

This weekend at the range I saw a Sig P938 fail to extract because the extractor did not grab the case. Tap-rack-bang didn't work, because the extractor still didn't engage. The shooter cleared the firearm and popped the spent casing out by shoving a rod down the barrel, and then put it back together and it started shooting and extracting just fine.

Any idea what would cause the extractor to fail to engage on one round in particular?

 

[sgt127]

Bad case rim. Extractor had crud under it holding it away from the rim. Tore through the rim? Swollen case. Just initial thoughts.

 

[Walt Sherrill]

And, of course, there is the possibility of a damaged extractor... (check the "tip/claw" for chips, breaks or similar damage.)

If any real force was required (using that dowel/rod) to dislodge the casing, that would suggest something might not be quite right in the chamber. Those kinds of rounds usually come out pretty easily, otherwise.

(Trying to get an extractor to catch a rim once it's missed seldom works.... You're often just slamming the case against the barrel/chamber, and there's often little or no way for the extractor to catch the rim.)

This is likely an issue ONLY if it continues to happen. Otherwise, it might be considered a round/case issue, rather than a gun issue.

 

[Steve C]

This weekend at the range I saw a Sig P938 fail to extract because the extractor did not grab the case. Tap-rack-bang didn't work, because the extractor still didn't engage.

When a case sticks in the chamber due to high pressure, rough or dirty chamber or other reason the slide doesn't retract and the case remains in place. The extractor really doesn't drag out a fired case. The fired case is expelled by pressure and the opposite reaction inertia produced by the fired bullet that pushes against the breach and shoves open the slide along with the case. The extractor really acts as a pivot point for the case ejection. Extractors only pull out the fired case of a gas operated gun or unfired rounds when the side is manually operated on blow back and recoil operated handguns.

If the case sticks in the chamber the "extractor" may not remove it when the slide is manually operated as it doesn't have enough grip to pull it out.

 

[chris in va]

Weak extractor spring too. Had that issue with one of my CZ's until I installed a Wolff spring.