This is a good overview of squib loads. If you want to load your own ammo take note- squibs most often happen on reloads. This has nothing to do with remanufactured ammo- it typically has to do with paying attention to what you're doing when you run the press. I only had this happen once and I can guarantee you I lost track of what I was doing at that moment and didn't have a good process for walking away from my press and resuming- it resulted in me seating a projectile in a cartridge that didn't have a charge. Anyhow here are a few salient points I want to reinforce about detecting and dealing with squib loads.
- Pay attention to the sound- when only the primer goes off it sounds different. If something sounds different while you're shooting, stop and check it out (DGU may be a different story but you shouldn't be using handloads in a defensive firearm).
- The unburnt powder depicted in the video may or may not be present. If something seems wrong check the barrel- it's not worth a KB in your hand, especially if you stop because something seemed peculiar.
- If this does happen to you, how to get the bullet out? It's typically best to back the bullet out the way it entered the gun. Normally that's also the shortest path too. Note that it may take a vise and you may trash a pushrod doing this…or you can always ask your friendly neighborhood armorer to take a look, but what fun would that be?