Welcome back to our discussion on Diagnosing Pistol Malfunctions. In Part 2, we will cover an in-depth analysis of Failure to Fire.
Unfortunately, most of us have experienced this at one time or another. We’ve inserted a loaded magazine, released the slide, chambered a round, disengaged the safety, aligned the sights in the center of the target, slowly exhaled while pressing the trigger, and as we felt the sear release the hammer or striker we heard a “Click” instead of a “BANG!”
On the range, it may be an annoying inconvenience to wait 30 seconds with the pistol pointed in a safe direction before “tapping” the base of the magazine, “racking” the slide to eject a possibly bad round and chamber what we hope to be a “good” one, “assessing” the target area, and deciding whether or not to fire again. In a personal defense, law enforcement, or military scenario, however, the most deafening sound has been described as the “Click” instead of the “BANG” required to stop the threat.
In the previous article, we covered malfunctions that occur during the first three steps in the cycle of operation: Feeding, Chambering, and Locking. In this article, we will focus solely on malfunctions that occur in the “Firing” stage.
Assuming the pistol has successfully fed, chambered, and locked, there are only two types of malfunctions that would prevent the pistol from successfully firing. These can be isolated to either the ammunition or the pistol’s ignition system. First, let’s cover ammunition failures.
If you recall from Internal Ballistics – Part III, we described pistol cartridge components: primer, case, propellant, and projectile. In order to focus this part of the discussion to ammunition, we need to assume that the pistol is mechanically functioning as intended and the cartridge is correctly chambered. Under these conditions, the ammunition failure must lie in the propellant or the primer.
Propellant – If there is an insufficient quantity of propellant in the cartridge case, the primer/propellant ignition chain will not produce enough pressure to propel the projectile all of the way through the barrel. This is known as a “squib,” and the shooter should notice an audible “pop” instead of a “BANG” along with an under-powered recoil. Regardless, this is a failure in a number of ways. First, the projectile will not impact the target. Second, if the shooter does not correctly perceive the squib and errantly attempts to fire again with a projectile lodged in the barrel, the overpressure caused by the next round will damage the pistol and potentially injure the shooter. If you detect the audible “pop,” stop firing immediately.
Primer – To briefly recap, the primer consists of a small metal cup that contains a pellet of sensitive explosive material secured by a paper disk and a brass anvil. A strike from the firing pin on the center of the cap compresses the primer composition between the cap and the anvil which causes the composition to ignite. Holes or vents in the anvil or closure cup allow the flame to pass through the flash hole in the cartridge case and ignite the propellant. The primer needs to be “tough” enough to withstand some jostling and extreme temperatures without igniting, but be malleable enough to fire when needed.
Again, in this section we’ve assumed that the cartridge is properly aligned on the breech face and the firing pin or striker has moved forward with enough force to ignite a normally functioning primer. However, there are some instances where the primer won’t function. First, the primer’s cap can be too thick or internal components can be incorrectly manufactured. Next, the primer can be set too low into the cartridge case and “out of range” of a normally functioning firing pin or striker. Lastly, an error in the cartridge manufacturing process can misalign, damage, or invert the primer. While all of the former defects would be difficult to ascertain, the latter can be diagnosed by visual inspection. (right inset photo)
Firearm Mechanical Failure
Turning things around, in this section we will assume that we have chambered a properly constructed cartridge, but a mechanical failure in the firearm itself is the cause of the malfunction. This leaves us to consider the following possibilities: (1) Something is preventing the firing pin or striker from moving forward with enough force to properly ignite the primer; (2) the firing pin is damaged; or (3) the firing pin or striker is moving forward properly, but the cartridge is misaligned
Firing Pin/Striker Impeded – In this case, we will look at two scenarios. The first considers that the firing pin/striker remains locked into place and the second considers that friction is impeding free movement.
Many different types of pistols employ an inertial firing pin or striker safety. If a pistol without this design was dropped or thrust forward and abruptly halted, the inertia of the firing pin or striker could cause it to move forward with enough force to ignite the primer. While it seems like this would be a rare event in which the pistol was dropped within a narrow margin of possible angles to cause enough inertia to ignite the primer, the inertial firing pin or striker safety was designed to prevent this from happening. However, I believe that there are more instances where this “safety” malfunctions and induces a stoppage than there are instances where it prevented an unintended primer strike. I have no hard-data or statistics to back this up… just anecdotal evidence. Regardless, if the parts that comprise an inertial firing pin safety break, wear, or fail to function, the primer or striker may become locked into place and prevent the pistol from firing.
The other consideration within this scenario is that something such as dirt, carbon build-up, an improperly functioning firing pin spring, or excessive lubrication is preventing the firing pin or striker from moving freely within the firing pin channel. In this case, something is causing enough friction to impede the forward movement of the firing pin or striker resulting in a “light” primer strike which would produce a dented primer but no ignition. If you experience light primer strikes and suspect that something is impeding the movement of the firing pin/striker, clean the firing pin/striker, spring, the entire channel, and the opening on the breech face.
Damaged Firing Pin/Striker – Although it is tucked well within the slide of a semi-automatic pistol, the firing pin/striker withstands a lot of contrasting forces. In pistols with hammers, the firing pin is held in position by tension provided by the firing pin spring until the hammer drops forward and transfers its momentum to the firing pin. This thrusts the firing pin forward within the firing pin channel so the tip of the firing pin can protrude through the breech face to impact the primer with enough force to crush the anvil, mix the components, and result in ignition. The primer’s ignition initiates propellant burn which leads to the rapid gas expansion that continues the firing sequence. As the rapid gas expansion forces the walls of the cartridge case against the inside of the chamber, forming a tight gas seal, it also forces the base of the cartridge case, and thus the primer, against the breech face and firing pin. Combined with the tension of the firing pin spring, this forces the firing pin back into the firing pin channel. The sequence is similar for striker-fired pistols where the differences are: (1) the striker is partially or fully cocked during the slide recoil process and is held in-place by the sear until the trigger is pressed; and (2) there is no contact from a hammer.
The preceding description sets the context to tell you that if the tip of the firing pin or striker is broken, there may not be enough material protruding through the breech face to ignite the primer.
Cartridge Misalignment – In “Diagnosing Pistol Malfunctions – Part I Failure to Feed,” we highlighted the importance of the extractor in the cartridge feeding process. With a properly tuned extractor, the rim of the cartridge case should glide beneath the extractor claw. Furthermore, the extractor should guide the base of the cartridge case straight up the breech face as the cartridge moves into the chamber. When all mechanical functions are operating properly, the cartridge case is held firmly in place with the primer centered on the firing pin hole on the breech face. As you can see in the embedded photo (click for a larger view), the firing pin/striker protrudes far enough to ignite even stubborn primers.
However, an out-of-tune extractor that fails to hold the cartridge case firmly against the breech face can cause a misalignment between the firing pin/striker and the primer. As you can see in the right inset photo, the firing pin made solid contact with the primer, but failed to crush the anvil and ignite the components.
Whether it is during recreation, competition, or in a personal defense scenario, we hope we never hear the deafening sound of “click” when we need to hear a “BANG.” However, hope is not a viable course of action. If you experience the “click” during recreational fire or during training, remember to keep the firearm pointed in a safe direction for 30 seconds before cycling the cartridge. During supervised training or competition, follow the Range Safety Officer and Range Officer instructions. In a self defense scenario, do whatever it takes to survive. In any circumstances, if you hear or feel anything that indicates a reduced charge or squib load, DO NOT FIRE THE NEXT SHOT until you have determined that there is not a projectile lodged in the barrel.
When diagnosing the cause of the failure to fire, start with the ammunition first. Evaluate the primer for no strike, a light strike, or an off-center strike. Off-center primer strikes are typically a product of improperly tuned extractors. Light primer strikes can be a attributed to either improperly seated primers or a mechanical issue within the firearm.
In the end, the best preventative measures are to keep your firearm clean, well maintained, well lubricated, and to inspect your ammunition prior to loading it into your magazines. A little attention on the front-end can prevent a lot of frustration later.
Next time, we’ll focus on diagnosing the final set of pistol malfunctions… failure to eject. Until then, stay safe and shoot straight.
– Howard Hall