It can also be caused by worn recoil springs, buffer springs, or simply a dirty feed ramp.

Failure to feed is common when the shooter does not hold the firearm firmly (known as limp wristing), when the slide is not fully cycled by the preceding round, or due to problems with the magazine.

In extreme cases, an overloaded round, blocked barrel, poor design, or severely weakened breech can result in an explosive failure of the receiver, barrel, or other parts of the firearm.įailure to feed (FTF) is when a firearm fails to feed the next round into the firing chamber. Mechanical malfunctions of a firearm (commonly called jams) include failures to feed, extract, or eject a cartridge failure to fully cycle after firing and failure of a recoil- or gas-operated firearm to lock back when empty (largely a procedural hazard, as 'slide lock' is a visual cue that the firearm is empty). Blank rounds use a type of powder different from that of other rounds, and generate much more pressure, which, combined with the presence of the projectile obstructing the barrel may cause the firearm to fail catastrophically. The bullet from a squib stuck in the barrel must never be cleared by subsequently attempting to fire a live or blank round into an obstructed barrel. In the case of semi-automatic or automatic weapons, this can cause subsequent rounds to impact the projectile obstructing the barrel, which can cause a catastrophic failure of the structural integrity of the firearm, posing a threat to the operator or bystanders. A squib load (also squib round, squib, squib fire, insufficient discharge, incomplete discharge) is an extremely dangerous malfunction that happens when a fired projectile does not carry enough force and becomes stuck in the gun barrel instead of exiting it.

Why do guns jam