Hangfire
Definition
A delay between firing-pin strike and cartridge ignition, ranging from fractions of a second to several seconds. Caused by degraded or moisture-contaminated primer compound, or insufficient firing-pin energy. Standard protocol requires 30 seconds of muzzle-downrange hold before opening the action.
- Definition
- Delay between firing-pin strike and ignition
- Duration range
- Fractions of a second to several seconds
- Causes
- Degraded or moisture-contaminated primer, weak firing-pin strike
- Safety protocol
- 30-second muzzle-downrange hold before opening the action
Common questions
Why is hangfire treated as a safety hazard rather than just a malfunction to record?+
The round can still fire after a delay, so an operator who assumes a simple misfire and opens the action too soon risks discharge out of battery or with the action open, which is why range protocols mandate a fixed downrange hold.
How does hangfire differ from a true misfire in forensic firearms examination?+
A misfire never ignites at all, while a hangfire eventually does, so distinguishing the two after the fact relies on evidence like a delayed report witnesses heard or examining the fired case and primer for signs consistent with delayed rather than absent ignition.
What primer condition most commonly produces hangfire?+
Aged or moisture-degraded primer compound is the most common cause, since it slows the priming compound's ignition chain reaction without stopping it entirely.
Related terms
- Chamber Pressure
- The gas pressure inside the firearm's chamber and bore during combustion of the propellant charge. Measured by piezoelectric transducer in psi (SAAMI)...
- Maximum Average Pressure (MAP)
- The SAAMI statistical ceiling for mean chamber pressure across a production lot of cartridges, at specified temperature and barrel conditions. CIP uses...
- Piezoelectric Transducer
- A quartz or ceramic crystal sensor mounted in a barrel port that converts chamber pressure to a measurable electrical charge. The basis...
- Slamfire
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- Squib Load
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- Throat Erosion
- Wear of the bore at the point where the rifling begins (the throat or leade), caused by hot propellant gas and bullet...