Probably one of the most common skills taught in defensive handgun, after Shooting Fundamentals and the Draw of course, is an Emergency Reload.
An Emergency Reload occurs when in the midst of an engagement, the magazine empties and the slide of a handgun or bolt of a rifle locks to the rear. In this moment, it's quite critical to quickly clear out the empty magazine and load a fresh one so that you can return to firing as soon as possible.
Now there are lots of ways that the technique of Emergency Reload is trained, but in a lot of cases one half of the training is MISSING! That half, and I'd argue, the most important half, is the Stimulus Response to the firearm emptying.
If you watch most shooters, the moment their firearm empties, they will generally stop, look at the firearm, process what happened and THEN try to fix it. The problem here, is that at the defense of your life, you don't have time for all of that.
This drill set will help you build that second half of the neural pathway of an Emergency Reload, the Stimulus Bridge. Check it out.