The first reason that I don’t recommend assisted opening or auto knives for personal protection comes from not edged weapon observation, but rather firearms.
Those that carry a pistol for personal protection usually put some thought into doing so. They also clean their gun and ensure there is a round in the chamber. That is probably why they experience a second of shock when they draw their pistol, especially under stress, pull the trigger and hear the deafening sound of silence. For some reason the gun did not go back. Expect for those who train otherwise, there are two common reactions. The first is that they just freeze in disbelief and stare at the gun. The second is that they perform an immediate action drill to either clear the malfunction or just chamber a round. If the malfunction cannot be cleared on the first try, almost all people fixate and stare at the gun in disbelief. Their world gets very small, very fast. This does not matter much if you are shooting at cardboard, but if someone is rushing you with a weapon, both reactions will get you killed.
Back to assisted openers and autos. As far as I know, and I may be wrong, there are no companies making a trainer for their knife. So that means any practice you do must be done with the live blade. I believe that very few people’s common sense would allow them to train at full speed with a live knife, even if it is just working on deploying the blade. And certainly nobody would be able to find a training partner to rush them, much less make contact with them as they are doing so.
The grip needed to deploy the blade is usually not what you would consider the best fighting grip. Most people who have only fiddled around with an assisted opener or auto knife have had times when the blade failed to deploy for some reason, whether it was contact with a pocket or something else. Before we get into how to solve the problem, first let’s discuss it. How would you know that your blade did not deploy? Well, you would either not hear it click, unlikely due to auditory exclusion. You might feel it as it cuts into the back of your fingers as you acquire your fighting grip and the blade is forced down upon contact with your aggressor. Or lastly, you look at the blade to and see it is not locked open. If you are looking at your knife, you are not looking at the threat. What would your immediate reaction be? Try to fiddle with the knife to try to open the blade again? Do to vasoconstriction that is going to be a dicey option.
Of course this could be said of any folder. That is why we teach that deploying the knife from the pocket and the blade from the knife as two different distinct steps. Also built into the draw is a failsafe in case you begin to drop the knife as it is deployed from your pocket. Another step of the drill is using the closed knife as an impact weapon if deadly force is no longer justified or you don’t have the time and space to deploy the blade. The whole thing is built around the solid belief that shit happens. What you can’t avoid, you plan for.
Of course there are those who say “that is why I carry a fixed blade”. I would bet that they are also the ones who talk about how you need to carry a 1911 but have a habit of putting a 38 snubbie or a 380 in their pocket when they venture out.
The reality is that for lots of people because of laws, company policy, or comfort are armed only with a folding knife as a deadly force option. This makes it even more important that they have confidence in that knife and their skill in deploying and using it. Our common sense approach to tools is selection, carry, deployment, and use. Out of those the stumbling point is deployment. Don’t make things harder on yourself by carrying a knife that relies on a spring to work properly.
