The Mouse Gun

Mouse guns are tiny and easily concealed. They are light and convenient. At one time in history, they were referred to as “ladies’ guns” or derringers…
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Mouse guns are tiny and easily concealed. They are light and convenient. At one time in history, they were referred to as “ladies’ guns” or derringers…

There is a vague category of small handguns that are both loved and hated throughout the world of shooting. They are called “mouse guns.” Rumor has it that the term “mouse gun” was coined by Massad Ayoob. It does not refer to firearms that are specialized for hunting small rodents or shooting computer accessories. Regardless of the origin of the term, it refers to small, weak caliber handguns that were designed with concealment as a priority, rather than “knockdown power.”


Risk factor analysis refers to the process of weighing two or more risks that are mutually exclusive.


In order to clarify the controversy, a brief review is in order. Jeff Cooper once said, “We hear of an unfortunate woman, who during a nighttime asthma attack, confused the small handgun she kept under her pillow with an asthma inhaler and proceeded to relieve her symptoms. It was not a fatal mistake, partly because she used a .25 ACP, which everyone knows is not sufficient to clear sinuses.” From his comment, one can easily see that Mr. Cooper does not have much confidence in the .25 ACP. Anyone who ventures into one of the multiple, internet, handgun, discussion groups will find this topic being resurrected and beaten like the proverbial dead horse. This article is one more kick at the old nag.

Mouse guns are tiny and easily concealed. They are light and convenient. At one time in history, they were referred to as “ladies’ guns” or derringers (early, two-shot, pocket guns which are still quite popular). They were placed in purses or pockets of prudent women of the era and carried with ease. Derringers were also used by nineteenth century, riverboat gamblers and therefore gained a shady reputation by association. During the past decade or so, the mouse gun has enjoyed a renaissance of sorts, as more Americans have begun to carry concealed handguns.

Gun experts, especially those with military or police experience, have become quite vocal in their disdain for the little pocket guns. Their reasoning is not based purely on prejudice. In fact, many of them have had first-hand experience in observing the failure of mouse guns in self-defense situations. They consider the small calibers of mouse guns relatively ineffective and therefore poor choices for self-defense. The controversial issue is whether or not the small calibers are worth carrying for defense at all. There are mouse pistols in .22, .25, .32 and .380, as well as derringers in many large calibers, such as 9mm, .357, and .45. This article is limited to discussing the smaller calibers. Rather than mull over endless ballistics tables, studies involving the shooting of unarmed sheep and goats, photos of shot up blocks of unflavored gelatin and long winded scenarios, it might be better to just look at the controversy in a different way.

Risk factor analysis refers to the process of weighing two or more risks that are mutually exclusive. In other words, two mutually exclusive events cannot occur at the same time. For example, let’s say that you need to carry a handgun in a certain public venue, but the social, career, or other [insert your own personal risk] fallout would be too great to bear if the gun were noticed.


…one should weigh their own, personal, risk factors very carefully and understand the possible consequences of their compromises.


For whatever reason, you absolutely cannot have your handgun noticed in this situation, but if you feel as though it would be prudent for you to carry one, you must analyze the risk factors. If the risk of having your gun seen has no relevance or detrimental effects in your life, then by all means, carry your big gun and forget about the mouse gun. Your big gun has been proven beyond a doubt to be much more effective and accurate. However, for those who are not so unencumbered by society, the art of compromise is much more important.

Making blanket statements can be foolhardy. Rarely does a “one size fits all” approach succeed. It is crucial to make decisions by correctly weighing the risk factors.

Your life and the lives of those that you claim to protect and be responsible for may depend upon it. Thankfully, the powers that be have created a wide variety of calibers and configurations, so that people can make their own choices, according to their individual needs. It is certainly not an “all or nothing” proposition.

Let us first emphasize the obvious. Bigger, more powerful rounds make bigger holes and go in deeper. If one shoots an aggressor (human or otherwise), one would naturally want their bullets to make holes as big and as deep as possible, to cause enough damage to stop the attack. The issue is more complex, but this is the basic truth. Of course, a logical deduction would be that one should carry a firearm that shoots those large rounds.

Concealed Carry rarely does a “one size fits all” approach succeed.

Rarely does a “one size fits all” approach succeed.

Shotguns and most rifle calibers have better knockdown power than handguns. Rifles have better range than both handguns and shotguns. Although shotguns and rifles may be practical for home protection use, carrying one concealed is nearly impossible and also illegal in most states. The handgun is the weakest of the three, yet it is favored for concealed carry because of the convenience of its size and format and also because it has less social and legal constraints. As you can see, the art of compromise has already begun.

Now consider the mouse gun in this framework. Most small handgun calibers have performed poorly as “man-stoppers” in almost all ballistics tests. Most reputable gun trainers disparage the mouse calibers as terrible choices for defensive purposes. Why then consider these poor performers? What social constraint can you imagine that would limit the size of the handgun that you could carry?

Let’s imagine a waitress who has been issued a uniform by her employer that simply will not conceal a Mil-Spec, Springfield 1911 on her 105 pound body. It is forbidden to wear a fanny pack while on the job. She cannot hide a .38 snubby, a compact .45 or a small 9mm auto. She works in a “nice place,” but you remember a story about a Luby’s cafeteria in Texas that was also a “nice place,” so she would like something more than harsh words and pepper spray in case a rare, but terrible event should occur. Would a Kel-Tec P32 or 3AT be a possible compromise? Maybe they are yet too large to conceal in her form-fitting uniform and she has to resort to a NAA mini revolver that just barely hides in her pocket, vs. no protection at all! There are many scenarios that one could insert here, both pro and con, such as exotic carry systems that may be employed in order to allow her to carry a larger weapon, but these systems usually don’t actually work as well as their marketing implies.

Mouse guns are tiny and easily concealed. They are light and convenient. They were placed in purses or pockets of prudent women of the era and carried with ease.

…people can make their own choices according to their individual needs.

Most successful carry systems are conventional systems such as belt, shoulder and ankle holsters, purses and fanny packs. A waitress in a typical uniform (a dress) will probably have no pants for a belt holster, nothing to cover a shoulder holster, and exposed ankles. Some people have had success with special holster underwear and the like, but they all have their own levels of compromise. Some are acceptable and others are not. Men, who can usually wear long pants or a jacket in public, may be less limited than women, but most men have female loved ones who have much less choice in the matter.

Our imaginary waitress must weigh the risk factors. She cannot afford to startle a customer and thereby loose her job. She will not go unarmed, because she has decided that she does not need a man to protect her nor would he be available 24/7 if she did. She has obtained training and is proficient in the use of handguns. She knows the limitations and weaknesses of mouse guns and has considered the risk of the compromise. She has investigated the different choices and has tried to get the most powerful, yet controllable model that she can conceal in her uniform. Of course, when she is not in uniform, she should carry a more potent handgun, but until she is independently wealthy and doesn’t need her job that requires such a uniform, her mouse gun must be an acceptable compromise at work.

The controversy may be partially caused by the comparison factor. When comparing a .45 ACP coming out of a four inch barrel to a .32 ACP coming out of a two inch barrel, it does not take a doctorate in physics to choose the .45 ACP as the clear winner. It may be more practical to compare a shot from a .32 ACP to a dose of pepper spray or a touch from a stun gun. Some may argue that a trained practitioner can do more harm with a tactical, folding knife than with a mouse gun, and in a shorter amount of time.

That may be true, but the mouse gun can be used from a greater distance than a knife and it can also be used by those less physically inclined than the agile, knife fighter.

She will not go unarmed. Mouse guns are tiny and easily concealed. They are light and convenient. They were placed in purses or pockets of prudent women of the era and carried with ease.

She will not go unarmed…

Unless one has excellent karma or razor sharp skills, it is unlikely that one would get a “one shot stop” with a mouse gun, especially under extreme stress, but small calibers have been used successfully many times. Many police carry a BUG (backup gun). These BUGs are often mouse guns. They understand that the BUG is a far cry from their primary weapon, but many policemen have been saved by their little, wimpy, mouse gun when their primary weapon failed.

Other factors concerning mouse guns must be considered. Mouse guns are difficult to shoot. If they shoot a fairly large caliber, they can have punishing recoil. The weight of larger guns absorbs some of the energy produced by recoil, thus making them easier to shoot. Mouse guns have less mass and therefore much of the energy from recoil is transferred to the shooter’s hand. They are also difficult to aim. Short barrels and tiny grips make them inherently inaccurate. It is unlikely that a mouse gun would be successfully used beyond a short distance.

In summary, one should weigh their own, personal, risk factors very carefully and understand the possible consequences of their compromises. Carry the most powerful handgun cartridge that you reasonably can, while considering accuracy, handling and format quality. Consider the mouse gun to be a last-ditch weapon, which certainly has its place, but shouldn’t be compared to larger calibers. A wise man once said that a .32 ACP in your pocket is better than a .45 ACP left at home.


[ Charles is a Quality Systems Manager in manufacturing and an artist. He is an occasional, guest writer for CCM, and he especially advocates self-defense for women. He believes that the Second Amendment is all about political freedom and self-defense, rather than duck hunting. He also thinks that he might be the only Jewish, Libertarian (who votes Republican), vegetarian member of the NRA. Charles also runs a pro-liberty blog at :

Kathleen is an nutritional herbalist in order to survive health-wise, and a pistol-packer in order to survive security-wise. She is also a writer and the new copy editor for CCM. She has the same political beliefs as Charles, and no, they’re DEFINITELY NOT hippies.

Charles and Kathleen have been exceptionally, happily married for twenty-three years. ]

One Comment (Add Yours)

  1. Good real-life scenario there. I’m a factory worker, a commercial sewer. I don’t have a company-issued uniform, but I do have a company “no weapons” policy (which did not prevent a guy who was angry about being fired from picking up a piece of steel pipe and putting a 6’4″, military veteran into the hospital). If my gun is detected I will be fired.

    I work bent forward over a sewing machine or bent over a table to mark material, which rules out both appendix carry and hip carry — the former due to the gun digging in, the latter due to printing. I’ve had belts and zippers fail on 2 fanny packs in less than 2 years even though my Taurus Slim isn’t all that heavy.

    So I’ve bought an MPA Protector 380. In the “universal” holster from the latest failed bag, it fits undetectably in my bra (42DD offers more potential than a smaller size). It will fit in a belly-band worn on the ribs (the Slim may or may not depending on the outfit).

    It certainly beats relying on my thread snips or my box cutter.

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