A firearm malfunction glossary is useful because gun people have a bad habit of using one word—”jam”—for a dozen completely different problems.
That is fine when everybody at the range knows what happened. It is not very useful when you are trying to diagnose a firearm.
The exact symptom matters. A failure to feed is not the same thing as a failure to extract. A stovepipe is not the same thing as a double feed. A light strike is not automatically an ammunition problem.
This glossary translates the most common malfunction terms into plain English so you can describe what the firearm is actually doing.
Firearm Malfunction Glossary: Failure to Feed — FTF
A failure to feed occurs when a fresh cartridge does not move from the magazine into the chamber correctly.
The round may nose into the feed ramp, stop partway into the chamber, sit too low for the slide or bolt to pick it up, or become trapped at an angle.
Possible contributors include magazines, ammunition, feed geometry, spring condition, cycling speed, fouling, or parts compatibility.
Failure to Chamber
A failure to chamber happens when the cartridge begins feeding but does not seat fully in the chamber.
The action may stop short of its normal locked position. Causes can include chamber fouling, damaged or improperly sized ammunition, feed-path problems, extractor-related resistance, or another mechanical issue.
Out of Battery
A firearm is out of battery when the action is not fully closed or locked in the position required for normal firing.
Depending on the design, the firearm may prevent the shot from firing. If a firearm repeatedly fails to return fully into battery, that is a symptom worth investigating rather than forcing the action closed and continuing.
Failure to Extract — FTE
A failure to extract means the fired case remains in the chamber or is not pulled rearward correctly after firing.
The extractor, chamber condition, ammunition, spring tension, and operating cycle can all matter.
Failure to Eject — Also Called FTE
Confusingly, shooters also use the abbreviation FTE for failure to eject.
In this case, the fired case leaves the chamber but fails to clear the firearm. It may remain loose in the action or become trapped by the slide or bolt.
When talking to a gunsmith, saying “failure to extract” or “failure to eject” is clearer than just saying FTE.
Stovepipe
A stovepipe is a type of ejection malfunction most often discussed with semi-automatic pistols. The empty case becomes caught in the ejection port, often standing upright or nearly upright like a small stovepipe.
Repeated stovepipes can be associated with inadequate cycling energy, worn recoil components, fouling, lubrication issues, ejector damage, ammunition, or other mechanical conditions.
Double Feed
A true double feed generally means two live cartridges are trying to occupy the feeding path or chamber area at the same time.
The term gets used loosely, which is why the physical evidence matters. If a fired case is still stuck in the chamber while a live round tries to feed behind it, that may look like a double feed, but the root problem often began with extraction. If two live rounds are released together, magazine feed-lip, follower, or spring problems move much higher on the list.
Nose Dive
A nose dive occurs when the front of the cartridge drops downward instead of rising smoothly toward the chamber during feeding.
Magazine spring strength, follower design, feed-lip geometry, cartridge shape, and the relationship between the magazine and feed ramp can influence this symptom.
Failure to Fire
A failure to fire means the trigger is pressed but the cartridge does not discharge.
Possible causes include ammunition, primer condition, firing-pin or striker problems, insufficient firing-pin energy, the firearm being out of battery, trigger or fire-control problems, or debris in the firing-pin channel.
Light Strike
A light strike describes a primer impact that appears shallower or weaker than expected and does not ignite the cartridge.
Light strikes can involve ammunition, weakened springs, contamination, incorrect parts, excessive friction, firing-pin or striker damage, or other fire-control conditions.
A single misfire does not automatically prove a light-strike problem. The primer, ammunition lot, and firearm all matter.
Failure to Reset
A failure to reset means the trigger or firing mechanism does not return to the condition required for the next normal shot after the action cycles.
This can involve trigger components, springs, connectors, sear surfaces, improper assembly, contamination, or aftermarket parts that do not interact correctly.
Short Stroking
Short stroking means a semi-automatic action does not travel far enough rearward to complete the normal cycle.
On an AR-pattern rifle, that can cause weak ejection, failure to pick up the next round, failure to lock back on the last round, or other cycling symptoms.
Possible causes include insufficient gas or cycling energy, excessive friction, fouling, ammunition, spring or buffer configuration, or mechanical faults.
Bolt-Over-Base Malfunction
In a bolt-over-base feed malfunction, the bolt or slide moves forward but rides over or catches the cartridge incorrectly instead of feeding it normally from the magazine.
Magazine position, feed-lip geometry, spring strength, cycling speed, or action travel can contribute.
Failure to Lock Back
A failure to lock back occurs when the slide or bolt does not remain open after the last round when the firearm is designed to do so.
This can involve the magazine follower, slide-stop or bolt-catch components, shooter contact with the control, spring condition, ammunition, or insufficient cycling travel.
Failure to Return to Battery
A failure to return to battery means the action does not close completely after cycling.
This can result from a dirty chamber, feed resistance, recoil-spring problems, excessive friction, damaged ammunition, extractor issues, or parts fitment.
Hangfire
A hangfire is a perceptible delay between the firing mechanism striking the primer and the cartridge actually firing.
Because delayed ignition can create a serious safety issue, keep the firearm pointed in a safe direction and follow the firearm and ammunition manufacturer’s guidance for a suspected hangfire.
Squib
A squib is an underpowered cartridge event where the projectile may fail to exit the barrel.
This is not something to “shoot through.” If a shot sounds or feels abnormally weak, stop firing and verify the bore is clear according to safe procedures before continuing. Firing another round behind a lodged projectile can catastrophically damage the firearm and injure the shooter or bystanders.
Case-Head Separation
Case-head separation occurs when a cartridge case fails and separates, potentially leaving part of the case in the chamber. This requires inspection before continued use.
Failure to Go Into Lockup
This term describes an action that does not reach or maintain the mechanical lockup required by its design. The exact cause depends heavily on the firearm platform and should not be treated as a generic cleaning issue if it repeats.
Why the Words Matter
When you tell a gunsmith, “My gun jams,” the next question has to be, “How?”
When you say, “The fired case stays in the chamber and the next round tries to feed behind it,” you have already provided useful diagnostic information.
Good terminology does not make somebody a gun expert. It simply makes troubleshooting faster and more accurate.
Bring the Evidence
If the malfunction is repeatable, note the ammunition, magazine, round count if known, recent modifications, and exactly where the cartridge or case ends up. Photos taken after the firearm is made safe can also help document an intermittent problem.
For deeper explanations, read our Field Reports on extraction and ejection problems, common feed problems, and when a firearm needs cleaning versus repair.
If the same malfunction keeps coming back, visit Gun Repair & Upgrades or contact Dog Will Hunt Armaments.
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