“Mouse guns” are super-small pistols and revolvers now all the rage among the concealed-carry set. Are they shootout life-savers or will they get you killed faster than Custer at the Little Big Horn?
A military truism states if you’re down to just your pistol, you’re having a bad day. If you’re down to your mouse gun, your bad day just got worse. African big game hunter Robert Ruark always advised, “use enough gun.” Famed firearms trainer and gun writer Jeff Cooper believed if you held anything less than a 1911 .45 ACP pistol during a gun fight, you should make a reservation for yourself at the morgue. Where does the truth lie when it comes to these little guns?
As with all complex realities, this question defies a simple answer. If handguns in general are imperfect tools for personal defense, mouse guns are more imperfect yet. A low-velocity .38 Special or .380 will not make as effective a wound channel in a human assailant as a .357 Magnum, .45 ACP, or 9mm. Physics is physics. Despite this inconvenient truth, more and more armed civilians as well as law enforcement officers flock each day to gun stores to buy sub-compact, sub-caliber handguns for either primary carry or backup.
If we admit these little guns are imperfect, then just two questions remain for anyone determined to carry one. Revolver or semi-auto pistol, and which mouse gun cartridge is best, if any?
Pistol vs. Revolver
This debate has gone on since the late 19th century and we won’t settle it here. However, when it comes to mouse guns, the question takes on greater weight. After all, these tools are a last ditch line between you and a body bag. Serious stuff, indeed.
Each type has its advantages and disadvantages. The final decision, I think, comes down to how you might have to use such a tiny fire-breather.
For general carry, and even backup, the small pistol has a higher rate of accurate fire for the average shooter than a double-action revolver. It is also easier and faster to reload. This is important because the rounds these guns spew forth are low on the power scale. Plan to empty the whole magazine into your assailant in hopes one or two bullets get in far enough to incapacitate them before they end you. If you face multiple adversaries, you’ll appreciate the fact you can change mags fast since you just went to slide lock on bad person #1. The mini-pistols are also easier to conceal than a small wheel-gun.
Give the revolver credit, though. It is the only gun here which will fire reliably if its muzzle is punched against a miscreant’s body. This is a plausible situation—for a backup gun, in particular. Try this with any semi-auto and you’ll bump the slide back far enough to render the gun impotent. Oops.
My basic rule: general carry—pistol; down and dirty belly-gun—revolver.
Best Mouse Gun Cartridge
Mouse guns eat small rounds for the simple reason they are small (duh). Nothing larger than .38, as a general rule (we’ll talk about the exceptions later). In this class, there are few, if any, standouts. They all produce similar, lackluster ballistics. Even the supposed king, the .38 Special, is anemic when fired from ultra-short barrels. Energy figures run from about 250 ft-lbs, on down. Not encouraging.
These cartridges—.38 Special, .32 H&R Magnum, .380 ACP, .32 ACP, .25 ACP, and .22 Long-Rifle—all operate at lower velocity, with some minor exceptions. This creates two significant problems. Even the best hollow point bullets in this class often fail to expand as advertised, and they penetrate less than the 12-inch FBI recommended minimum in ballistic gelatin.
Test after test show these rounds dig eight to ten-inch deep holes in gelatin, on average, with hollow points—when and if those bullets expand. Add in small diameter wound cavities, and you have a recipe for limited effectiveness. Get used to disappointment, as The Dred Pirate Roberts might say.
Because hollow points under-penetrate at these velocities, many people say, “Ah-hah! Just use non-expanding bullets.” This does enhance penetration, but at a price. .380 FMJ, for instance, will blow right through laminated car windshields, anyone sitting behind said glass, and stop who knows where. Risky stuff in today’s world populated with personal injury lawyers and politically ambitious prosecutors. Mouse guns require tough decisions.
The table below demonstrates just how close these rounds are to each other based on muzzle velocity and energy. Let's look at each one in more detail to determine if there is a clear winner among them.
Standard Factory Mouse Gun Cartridge Ballistics
|Cartridge||Brand||Bullet||Muzzle Vel. (fps)||Muzzle Ener. (ft-lbs)|
.38 Special +P
135 gr. GD JHP
110 gr. STHP
158 gr. LRN
.32 H&R Mag.
85 gr. JHP
85 gr. FMJ
95 gr. PDX1 JHP
71 gr. FMJ
65 gr. Hydra-Shok
50 gr. FMJ
35 gr. FTX
36 gr. HP
Around since 1898, the ubiquitous .38 Special is a fine self-defense round. With modern hollow-points, it gives appropriate penetration and reasonable width wound channels with controllable recoil. No wonder police around the world loved it for decades. In a four-inch or longer barreled, medium frame gun, that is.
Chop the barrel down to the 2-inch range, put it on a small-framed gun, such as Smith & Wesson’s Model 36 or Colt’s Detective Special, and the cop’s favorite morphs into a snappy little brat with so-so terminal performance. Super-light alloy frames just make matters worse in the recoil department.
Best bet is to go with higher pressure, Plus-P, loads if your particular gun is rated for them. This improves bullet expansion and nudges penetration closer to the acceptable low end on the FBI scale. Those with an air-weight gun may prefer standard pressure rounds after they sample the Plus-P’s bite.
Maybe Our Great-Grandfathers had it Right All Along (When it Comes to Snubbie Ammo, at Least)
.32 H&R Magnum
This little wonder is perhaps the true “Goldilocks” mouse cartridge—it’s “just right.” Introduced in 1984, Harrington & Richardson’s last brainchild got short shrift from shooters for years, but has seen a resurgence with the uber-small gun trend.
Similar velocity to .38 Special +P, yet milder recoil due to lighter bullets, the .32 H&R performs well in short barreled wheel-guns. It is perhaps a better choice in a mouse gun than its big brother, the .327 Federal Magnum which has a lot more recoil. Downsides are limited/expensive ammo selection and those light bullets can degrade penetration. Its limited popularity means there are few street shooting data points with which to draw firm conclusions on its effectiveness.
If you go .32 H&R, get the latest in hollow point designs to maximize its potential.
.32 Revolvers: Many Advantages, Few Drawbacks
American shooters turned their noses up at this John Browning creation for almost a century. Popular with police and armies in other countries (Europe, in particular), the .380 is a good mouse gun choice given the competition. It scores in the mid-to-high sixtieth percentile for one-shot stops in studies by several different scholars, which puts it on par with standard pressure .38 Special (9mm and .45 ACP FMJ, as well, but don’t tell the fan boys).
This round puts its owners in a bind when it comes to ammunition selection. All the .380 hollow-points on the market under-penetrate. As I said above, you can run FMJ, but it may prove your undoing if a slug gets through your assailant and smacks something consequential. Good cartridge in its class, but a tough choice as well.
.380 FMJ Produces Significant Penetration. Beware.
This 120 year old Browning design is far closer to the .380 in street effectiveness than many people think, and it has milder recoil. Guns chambered for this round are easier for people with weak hands to operate.
Another Euro police favorite, the .32 ACP is the largest cartridge which will fit into micro category guns such as Beretta’s Tomcat or the Seecamp LWS .32.
The .32 ACP makes a better case for FMJ bullets given its lower muzzle energy and bullet mass—it can use all the penetration help it can get.
John Browning (yep, him again) intended the diminutive .25 to duplicate .22 rimfire ballistics in a semi-auto pistol. This is as low as it gets on the mouse gun power scale.
While it has the weakest ballistics here, deployed at just the right moment, a .25 could save the day. Loaded with FMJ bullets, it should penetrate bone better than lead .22s, which means it has a fighting chance to stop an attacker with a brain shot. Don’t expect much from it if you don’t hit the central nervous system. Yes, your assailant my die. In the hospital. Days later. Which will provide cold comfort to your bereaved family.
This is a gun for when you cannot carry a larger gun, period.
Comprehensive .25 ACP Test: FMJ and Hollow Points
In times past, no reliable semi-auto .22 caliber mouse pistols existed, which meant most folks picked a revolver. Now, there are several semi-autos out there with which you can trust your life. Still, though, rimfire ammunition has a misfire rate far above centerfire cartridges. This is why the .25 ACP exists. .22 ammo is hotter than the average .25, but is best served from revolvers, just for insurance.
Is the .22 a viable defense cartridge? Put eight or ten high-velocity hollow points into an assailant’s heart from ten feet away and it should have the desired effect. Just don’t expect it to work miracles.
Typical .22 Handgun Ammo Performance
Combine the trend toward miniaturization with the American credo, “more is better,” and you get the Frankenstein mouse guns. These weapons are the same size (in most cases) as the traditional guns we’ve discussed, but are chambered for more effective cartridges such as 9mm Luger, .357 Magnum (ouch!), .44 Special, even 10mm (ouch, again). Never mind short barrels reduce their effectiveness.
The Charter Arms Bulldog, for example, places five, .44 Special rounds in a revolver which slots in between Smith & Wesson’s J and K-frames. It is also available in light alloy (ouch!). Smith, Ruger, and Taurus produce small frame .357 Magnums. Then there are several single-stack 9mm’s just a smidge bigger than many .380s.
These guns violate a basic rule I have. As a race car’s engine is balanced to its chassis, so too a gun must balance size, weight, and power. I’ve heard stories about people who have touched off a titanium framed snub-nosed .357 and dropped the gun from the recoil!
A fresh-caught trout is easier to handle. Any gun which forces you to re-establish your firing grip on the weapon between each shot, as these often do, prevents rapid, accurate follow ups. A bad thing when you need to fire multiple rounds at multiple assailants who are stoked on meth. If they have any useful purpose it is as a belly gun. Thrust into an attacker’s body in one last, desperate attempt to survive, their somewhat more powerful first shot could save you.
9mm Mouse Gun Outperforms .380 with Same Barrel Length
Final Mouse Gun Thoughts
Mouse guns have a place in this world. They are not toys. They can incapacitate or kill an attacker. They are the most concealable firearms extant, and make good last-ditch weapons. You can take these guns along when nothing else will fit, when they must stay hidden at all costs. I still hesitate to consider them primary carry guns, though. For just a bit more bulk, there are handguns which give you more power and/or magazine capacity for the awful moment when trouble finds you.
As far as ammunition, modern hollow-points are the most realistic choice. Better to accept borderline penetration than hit some innocent who's behind your intended target.
Even Jeff Cooper, the 1911 cult’s high-priest, said the first rule in a gun fight is to have a gun. The mouse gun you brought is superior to the full-size one you left at home.
This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.
Kelly Ann Christensen from Overland Park, Johnson County, Kansas on January 25, 2020:
Interesting article. Do you happen to know whether you can own more than one of these AND a Bible without the FBI pulling a David Karesh on you? He at least had the Sheriff trying to defend him, and they had their kids to send to the basement.
Jack Burton from The Midwest on June 27, 2019:
I've carried my Keltec P-32 in my front pocket for nigh onto 20 years now. It saved me from two thugs who targeted me and I didn't even have to pull it out of the pocket.