Ever since I bought a Chronos 1.4 high-speed camera, I have used it to document a lot of things. Most of them are firearm related. One benefit to having a high-speed camera is the ability to slow down fast events that are often too fast for our eyes to see let alone understand. One example is a firearm malfunction. We may know how to clear a malfunction but do we understand why it is happening so we can address the problem rather than perform remedial actions? Here we take a closer look at what causes a slow-motion malfunction.
Slow Motion @ TFB:
- Shooting a S&W Model 61 in Slow Motion
- DIY Schlieren Imaging of Bullets In Slow Motion
- Rifle Dynamics Slow-Motion AK Rifles
Understanding A Slow-Motion Malfunction
The video above has four different firearms that have a malfunction. All of them involve some stoppage due to the brass not getting out of the way. Often when we see these malfunctions, we clear it and continue shooting. However if it keeps persisting, we need to fix it. The problem is we do not know what causes the malfunction. We make educated guesses but that is all it is: a guess. But we have the technology, we can see a slow-motion malfunction and break it down.
My friend built this Krink himself. However every once in a magazine it will jam up. He thought the ejector or gas needed to be tuned. I filmed the slow-motion malfunction and you can see the brass hits the dust cover upwards, then bounces off the rear of the ejection port. This severely ebbs away the kinetic energy the brass had to properly eject. So instead it bounces back into the ejection port and the bolt slams closed.
The second slow-motion malfunction was another friend’s Flux Raider. He is using a full size slide and a compensator. the SIG P320 and FLUX Raider have had issues adding muzzle devices especially if you use a factory recoil spring. You can see the brass eject but at a leisurely pace. It does not get out of the way of the charging handle and results in a stove pipe.
I recall Roland Special Glocks having issues firing 115gr ball ammo and needed spicier loads to cycle properly. I believe that is what is happening here. Some of the rounds would eject but others would not. I told my friend to remove the compensator since he isn’t shooting spicy loads to make use of it anyway.
The next malfunction is from my Larue upper using a SureFire OBC. Yes it is dirty but this bolt and this upper have not had issues before. However, I have not run this bolt in this upper until now. There is a suppressor on the end of the barrel which would cause increased back pressure. In this slow-motion malfunction, the brass performs a sort of skateboard trick and rotates 180º in the ejection port but fails to leave. Changing the bolt back to the factory Larue BCG helped.
The final slow-motion malfunction is with a Big Horn Armory AR500 pistol shooting 350gr hollow points. The extractor lets go of the brass too soon so the only energy spitting it out of the chamber is the back pressure from the gas expanding. It seems the extractor or the spring need to be replaced.
Having the technology to see the unseen is extremely helpful and fun. I used to look at firearm malfunctions as a great training aid for practicing remedial actions. But now I feel like an explorer discovering something new with every slow-motion malfunction I record.