A firearm isn’t all that complicated, but it’s very important for every part to work properly. Remember, each time you pull the trigger, the bullet is propelled away from the gun by an explosion that takes place just a few inches from your hands and face. That’s definitely something that you want to happen properly to avoid injury.
One malfunction that is very serious is known as a squib round. When the gun is fired, a squib does not exit the barrel, but gets stuck. Much of the time, this means the round is totally invisible, and shooters will not understand what malfunction they had. They may shoot again, with the next round up, and fire that bullet right into the one that is stuck.