Handguns have come in different sizes for as long as there have been handguns. While soldiers and cowboys carried full-size black powder handguns like the famous Colt SSA revolver of 1872, which was 10.25” long with a 4.75” barrel, the gentlemen and ladies of society carried tiny guns that could fit into a pocket or handbag. The .45 caliber Wurfflein Phil Deringer manufactured in the 1840s only had a 2.5” barrel.

But the many handgun sizes available today and the names (nomenclature) that define them can quickly become confusing, especially to someone new to handgun ownership. It might be helpful, therefore, to put the various sizes of handguns into a framework for easy reference.

Why Handgun Size Nomenclature Matters

The word nomenclature is defined as a system or set of terms used in a particular science, discipline, or art. Descriptions of handgun sizes use terms like compact, subcompact, and micro-compact. These terms can be useful in light of all the internet articles and reviews many of us read, not to mention how many guns are bought based on little more than online sales listings.

Unfortunately, handgun size nomenclature is hardly an exact science. It’s not uncommon to read a gun review in which the author says something like, ‘The manufacturer lists this gun as a subcompact, but its size is closer to a compact.’ Nevertheless, it is useful to have a general framework that provides a quick reference of the size of a handgun and some of the benefits and drawbacks associated with it.

Handgun Size Nomenclature

Manufacturers usually assign a size label to their handguns, even though reviewers sometimes disagree with it. The two most common features used to determine handgun size are overall height and barrel length.

Overall height measures from the base of the grip to the top of the slide directly above it. Height is important in a carry gun because it is the length of the grip that has the greatest effect on concealability and the likelihood of a gun printing under a shirt or other cover garment. It also determines how easy it is to get a solid grip on the gun while firing it, and whether you will have your pinky hanging off the bottom of the grip. That can have a major impact on how well you can hold and control the gun when shooting it.

Barrel length affects the gun in a couple of ways. Ballistically, the shorter the barrel, the less time there is for the propellent to burn completely before the bullet leaves the barrel. The more completely the powder burns, the more velocity imparted to the bullet, although factors like the type of propellent can also affect it. The other aspect of barrel length is the sight radius.  The shorter the barrel, the closer together the front and rear sights are, which can affect accuracy over long distances. Since defensive handgun engagements are usually at shorter ranges, this isn’t as big a concern as it might be in target shooting. Also, if the gun has a red dot on it, the sight radius isn’t that important.

Another factor is weight. Weight affects how well a gun absorbs recoil. A smaller, lighter gun is going to be a lot more snappy to shoot than a heavier, larger gun that absorbs recoil better.  That will affect second-round accuracy in a critical situation. It can affect how often the owner practices with their gun. It’s no fun to practice with a gun that is painful to shoot.

There are a variety of labels that pop up in articles and descriptions, but practically speaking, they can all be grouped into four categories.

Full Size

A full-size pistol is a standard handgun. They are sometimes called service pistols or duty guns because they are the size carried by police and professional security officers. Overall height runs around 5.5” and barrels range from 4 to 5”. In 9mm, they generally have a capacity of 15 to 20 rounds with double-stack magazines. They are a bit large for most people to consider them good carry guns but excel as a home defense gun. They are the easiest to shoot well because they have ample grips and are heavy enough to absorb recoil.

Compact

Before the rush to subcompacts and even micro-compacts, other than pocket guns (I’ll get to them later), compacts were the primary choice for concealed carry. Compacts have a height of around 5” max and a barrel length of between 3.5 and 4”. The well-known Glock 19 is the classic compact pistol. They are the ideal jack-of-all-trades because they are easier to conceal than a full-size gun, but have better capacity and are easier to shoot than sub and micro-compacts.

Subcompact

Until the introduction of micro-compacts, subcompacts were the smallest practical concealed carry pistols you could get. They typically have a height of 4.5” or less, with a 3.1” to 3.5” barrel. Most manufacturers label their small single-stack pistols like the Walther PPS as a subcompact. However, there are double-stack subcompact-size guns available. Although wider than single-stack pistols, they generally have the same height and barrel length dimensions.

Although a bit more difficult to shoot and grip than a compact, subcompacts provide a good alternative when the environment is less permissive, or you are dressed such that concealing even a compact might be difficult. By the time you get down to the subcompact size range, most shooters will find that their pinky hangs off the bottom of the grip unless the magazine is inserted, providing a place for the bottom finger.

Micro-compact

The micro-compact size of handguns entered the market in 2018 with Sig’s introduction of the popular P365. Micro-compacts are small, easy-to-conceal guns that are usually  4” or less in height, and have a barrel of length of 3”.  The most significant aspect of this size is the thin width, generally being only around 1”. While some micro-compacts are available in 9mm, many of the smallest are .380ACP.

Although easy to conceal, even when dressed in summer clothes, micro-compacts amplify the disadvantages of subcompacts when shooting them. Their small size can make them snappy and difficult to control when compared to a full-size or compact handgun. The short grips mean that you will practically always have your finger hanging off the bottom of the grip, even with the magazine inserted. Magazine extensions are available to correct the problem, but using a magazine extension lengthens the grip, negating one of their benefits and making them more likely to print through tight clothing.

Other Size Nomenclature Terms

If you spend much time reading about handguns, you will run into some other terms based on the sizes and types of guns.  Some of these refer to subcategories of the other size categories, and others refer to a different family of guns altogether.

Long-Slide

A long-slide handgun is essentially a subcategory of full-size guns with an extended slide mounted on it. Long-slides are primarily used for handgun competition shooting. The increased length of the slide allows for a longer barrel and a longer sight radius, both of which can increase accuracy at longer ranges.

Pocket Guns and Mouse Guns

These terms refer to a class of tiny guns that are often smaller than even micro-compacts and frequently shoot very small caliber cartridges like .22LR and .32ACP. They are extremely easy to conceal, and some can be safely carried in the front pocket of a pair of jeans with the use of a proper pocket holster. The trade-offs for their ease of concealment are that they are not easy to shoot, often use low-power ammunition, have a very short range, and usually have a low capacity of 5 or 6 rounds or less.

Derringers

Derringers are a family of small, single-action guns that have been around for well over a hundred years. They can be a single-barrel or double-barrel, load through a break action, and require the shooter to cock the hammer before firing.  They are available in every caliber from .22LR to .50AE but are most popular and practical in smaller calibers like .22LR and .38 Special. They are small, often with 2” to 3” barrels and a height of 3” to 4”. Their drawbacks are their low capacity of 1 or 2 rounds and their abbreviated grips, which can make them difficult to shoot accurately.

A Word on Revolvers

Revolvers do not generally use designations of the same size as autoloading pistols. Barrel length is the most commonly used measure of a revolver’s size, although some companies, like Smith & Wesson, also assign designations like small, medium, and large to describe frame sizes. Others have begun manufacturing small revolvers specifically designed for concealed carry, like Ruger’s LCR (Lightweight Compact Revolver), but they are not that common.

If you are looking for a revolver for concealed carry, focus on the frame size and barrel length. Another factor is whether the handgun has an exposed or internal hammer. Concealed carry revolvers frequently have an internal hammer to eliminate the potential for it to become hung up when being drawn.

Conclusion

Handgun size nomenclature categories are useful in helping you decide how well a gun will fit your lifestyle and needs. Unfortunately, the categories are not hard and fast and can be open to interpretation. Always remember that no amount of written description, no matter how accurate, can ever be a substitute for holding a gun in your hand before buying it.