In some circles the pistol-mounted light has become quite popular as a personal-defense tool. The theory in the use of such lights is, of course, that you need to be able to identify the person as an actual threat before you employ deadly force. Further, we find that when we light up the target at night or in poor light, we can deliver our hits with much greater accuracy. However, there are some problems that can arise with the use of pistol-mounted lights that the defensive shooter should consider before making the transition.
Armed citizens often have two problems when considering carrying the defensive handgun. The first is that a suitable pistol, in a substantial caliber, often seems heavy, especially when one has been wearing it all day long. The other is that this same pistol can be more difficult to conceal. Unfortunately, mounting a light on the defensive handgun makes it even heavier. And it makes it more difficult to properly conceal the handgun.
Another potential problem that occurs when a person is using a pistol-mounted light is that he is tempted to use the pistol as a flashlight. I know of several cases in which the defensive shooter shined his light—and loaded pistol—on people and things that he had no intention of shooting.
The first of these issues, holstering, is dealt with by selecting the proper holster for use with a pistol-mounted light. A number of companies offer such holsters, in Kydex or leather, that will get the job done. However, the trade off is that these holsters are heavier and more bulky than traditional concealment rigs.
In order to avoid pointing your pistol at person and things that you don't want, or need, to shoot, it is virtually necessary to carry a second defensive light. The shooter uses the hand-held light to observe his surroundings and only goes to his pistol-mounted light when a threat has been identified.
The first is an equipment solution and the second is a training solution. And then there are those who follow the suggestion of the late firearms instructor Louis Awerbuck, who cautioned his students, “Don't hang 'stuff' on your pistol.”
I have tended to follow this line of reasoning. I generally carry some sort of 1911 pistol and don't want it to be heavier and harder to conceal than it already is. I carry a high-intensity defensive light in a convenient pocket to deploy, with or without the handgun, when I need to check my immediate area for a threat in poor light. It avoids both the holster issue and the gun safety issue.
The one exception that I make to this is a pistol that is a dedicated nightstand gun or car gun. I'm not wearing this gun, so the issue of having a light attached is not a problem. In both cases, I do have a hand-held light nearby to use for looking and seeing.
Whether a person chooses to employ a pistol-mounted light is a personal one. The defensive shooter just needs to be aware of the holstering and safety issues if he or she chooses to do so. Proper equipment choice solves one issue and proper training solves the other. For those who still have an issue with this technique, a hand-held defensive light and training in the several methods of deploying it along with the defensive handgun will work equally well.
Using a pistol-mounted light is not really a debate issue much as it is a personal-choice issue. The defensive shooter needs to become educated and informed, and then make the choice that works best for him or her.