The dangers of squib loads

What's a squib load you ask? It's when, instead of a bang following the squeezing of a trigger, one hears nothing or a pop. Typically, the situation is associated with a barrel obstruction in that the bullet of the round just "fired" hasn't cleared the barrel and is now obstructing it instead. The danger of the situation is that someone who isn't paying attention will simply eject the just "fired" case, chamber another round and squeeze the trigger again. Kaboom!

The most common manifestation of a squib is a round constructed without a powder charge; primed case, bullet, but no powder. Apparently, the pressure developed by a fired primer in the small space of a pistol calibre cartridge is sufficient to drive the bullet partway down the bore. The question I always had: will the bullet be driven far enough down the bore to allow the unobstructed chambering of another round in the chamber? Here we find out.

For this experiment, I built a powderless 45 ACP squib using a Remington 185gr JHP bullet and fired it in a model 21 Glock. Note, that this should not shed poor light on Glocks. This was an INTENTIONAL squib. After chambering and firing the squib, I disassembled the weapon and looked into the bore. Sure enough, the bullet was stuck slightly ahead of the chamber.



How far in is the bullet? To answer this question, we use some high tech measuring equipment; a chopstick, a black, felt-tipped marker and a measuring tape.

We first insert the fired case into the chamber, and ascertain where the base of the case sits with respect to the barrel.


We then remove the case, stick the chopstick into the breech-end of the barrel as far as it will go (until it touches the barrel obstruction) and mark the chopstick at the point where the base of the case would be.


Finally, we remove the chopstick and place it on a tabletop alongside the tape measure. We now remove the bullet obstructing the barrel by placing a wood dowel into the muzzle end of the barrel and then gently tap the dowel into the barrel until the obstructed bullet pops out the breech end of the barrel. We then line up the case alongside the chopstick so that the base of the case is flush with the black mark on the chopstick, and the end of the chopstick is flush with the base of the bullet. Tada! We have a measure of how far the bullet traveled down the bore before it stuck.


By my measure, the bullet was forced down the barrel a good half-an-inch past the case mouth ... JUST ON PRIMER PRESSURE ALONE. That's certainly enough to allow an unobstructed chambering of another round behind it, potentially leading to a dangerous kaboom for one who is not paying attention.

You have been educated ... and warned. Be safe and remember: the only safety you can rely one is the one between your ears.