Every firearms instructor worth their salt will tell you that when it comes to choosing a defensive handgun, or any firearm for that matter, that function is the number one consideration. That advice is really is a no-brainer or a truism. We give constant lip service to the fact that the top quality of any firearm chosen for combat or fighting is reliability. However, the truth of the situation is that more than a few online tactical gurus and gun shop experts favor popular mythology over reality based on experience and fact. For instance, the non-stop drivel about the .45 ACP overshadowing the 9x19mm cartridge in the “stopping-power” arena still abounds.  First of all, there is but a fraction of…