An automatic handgun can hold anywhere from  2 rounds to 100 hundred rounds, depending on the magazine. However, many automatic pistols come from the factory with magazines that hold between 6 and 18 rounds. Traditional revolvers can hold between 5 and 6 bullets. There are various factors that impact the magazine capacity of a particular handgun. Firearm make, model, caliber, size, and magazine all impact the number of rounds the handgun can hold.

There are six factors that will determine the maximum number of rounds any given firearm can hold. Sometimes maximum capacity can be increased with aftermarket magazines. However, sometimes the number of rounds a handgun can hold is limited by the handgun design. If you are looking to purchase a handgun, the following attributes will impact the maximum number of rounds a handgun can hold.

  1. Type of handgun (automatic, revolver, or Derringer/pocket pistol)
  2. Handgun size (full-size, compact, or subcompact)
  3. Caliber of the pistol (.38, 9mm, .45 ACP, etc.)
  4. Magazine layout (single stack or double stack)
  5. Aftermarket magazines
  6. Make and model of the pistol


How Pistol Type Affects The Number Of Rounds

There are essentially three types of handguns. The first, and one of the most common types of handgun, is the automatic reloading pistol. This type of pistol has a single chamber, and rounds are loaded automatically from a magazine as bullets are fired. The limiting factor on an automatic is the capacity of the magazine.

Next, on our list of handguns, we have the revolver. Unlike automatic pistols, revolvers have multiple chambers, which each house a single round. These chambers exist within the “wheel” of the revolver, and the number of chambers is set during manufacturing. As the trigger is pulled, or the hammer is cocked, the wheel rotates and aligns the next round in succession with the firing pin.

Finally, we have Derringer style pistols, which are sometimes referred to as pocket pistols. While not completely accurate, pocket pistols have become synonymous with the true Derringer pistol. Similar to revolvers, Derringers have a fixed number of chambers that each house a single round. However, there is no wheel that rotates. Instead, rounds are fired in a specific sequence if the pistol has more than one chamber.

There are several variations of pocket pistols. If the pocket pistol is an automatic, or a revolver then the number of rounds is dictated by the overarching pistol type. However, if the pistol is not an automatic and has no “wheel” then it is limited by the constraints of a Derringer.

How Handgun Size Can Affect Bullet Capacity

Generally, larger firearms are made to accommodate a larger caliber round, more ammunition, or both. While not always true, full size firearms can hold more ammunition than their smaller counterparts.

Given two firearms that fire identical caliber bullets, made by the same manufacturer, with similar magazine configurations (single stack vs. double stack), the larger firearm will be able to hold more rounds. All of this assumes the firearm is an automatic and not a revolver or pocket pistol.

Full size firearms which are the largest can hold the most ammunition. Compact models will have a slightly smaller magazine well, and therefore hold fewer rounds. The smallest size is a subcompact handgun and will have even less space for a magazine.

The Effect Of Caliber On Handgun Capacity

If handgun size can affect the number of rounds the pistol can hold, then ammunition size plays a similar role. Pistols that fire a smaller round can potentially carry more ammunition. However, the other factors on our list also impact the number of rounds a pistol can hold.

If there are two firearms with all the same characteristics except ammunition caliber, the handgun which uses a smaller caliber will be able to hold more ammunition. Because the magazine setup is the same, a smaller round will take up less space and therefore allow more rounds to be loaded. Again, this does not apply to revolvers or pocket pistols with a fixed number of chambers.

Magazine Setup And Ammunition Capacity

Automatic pistols are unique from the other types because they use a magazine rather than fixed chambers. Therefore, this section does not apply to revolvers and Derringer style pistols. With that said, magazines come in two different layouts, single stack and double stack.

Single stack magazines vertically align rounds into a column format. This type of magazine is usually more slender, which is great for concealed carry. However, this style of magazine is not the most efficient for increasing the number of rounds the handgun can hold.

Double stack magazines also align the rounds vertically, but the rounds are staggered essentially creating two columns instead of one. This method does make the magazine thicker, but allows more rounds to be loaded into a magazine of similar height.

Picture above is a single stack magazine from a 1911, a double stack magazine from a Sig 9mm, and a double stack mag from a Glock .40 caliber pistol. The 1911 has a single stack magazine that can hold 8 rounds. Both the Glock and Sig have double stack magazines that can hold over 10 rounds.

The Sig Sauer handgun can hold 15 rounds, while the Glock .40 caliber handgun can hold 13 rounds. Even though the magazine for the Glock is from a full size pistol it holds less rounds than the magazine from the compact Sig. This demonstrates how caliber, pistol size, and handgun model can impact the number of rounds a handgun can hold.

Increasing The Number Of Rounds A Gun Can Hold

If increasing the number of rounds your handgun can hold is of importance, then you’ll want to make sure you get an automatic. Due to the nature of their setup, increasing the number of rounds is a matter of creating a larger magazine. Aftermarket magazines are plentiful, and you can usually find larger magazines online or at your local gun show.

Above is an extended magazine for the 1911 model. This magazine can hold 10 rounds (as opposed to the traditional 8), but you’ll notice that when the magazine is inserted into the pistol that the magazine extends beyond the confines of the magazine well.

Unfortunately, if you have a revolver, there is not much you can do to increase the number of rounds your handgun can hold. The same can be said about Derringer style pistols or any pistol with a fixed number of chambers. Above is a picture of an older revolver, the fixed chambers do not allow you to easily add more rounds.

Variations In Round Capacity By Make and Model

If all of this wasn’t enough, the final determining factor for how many rounds a pistol can hold is the make and model of the firearm. As an example we’ll look at two comparable pistol models and examine how the number of rounds in the magazine can vary. First is the H&K P30 SK, and a Sig Sauer P365. Both are chambered for 9mm and are subcompact models. However, the H&K offers 10 round, 13 round, and 15 round magazines. Contrarily, the Sig only offers 10 round and 12 round magazines.

How Many Rounds Can An Automatic Hold?

Automatic reloading handguns hold a number of rounds equivalent to the size and setup of the magazine. Smaller single stack magazines will hold a minimum of 6 rounds. Larger double stack magazines can hold in excess of 19 rounds. Some manufacturers will provide a choice of magazines that have different capacities.

Additionally, the aftermarket magazine industry offers and abundance of choices for higher capacity magazines. For example, there are 100 round Glock drum magazines that you can likely find at your local gun show. While these are not ideal for concealed carry, they are available to gun enthusiasts. Before purchasing, make sure these magazines are legal in your state.

How Many Rounds Can A Revolver Hold?

The number of rounds that a revolver can hold is determined by the number of chambers bored out of the wheel. A revolver can generally hold either 5 or 6 rounds. Revolvers that have 6 chambers are more commonly known as six-shooters. Ironically, those with 5 chambers are not known as five-shooters.

Unlike their automatic counterparts, the amount of ammunition a revolver can hold is fixed by the number of chambers, so there’s no aftermarket upgrades to increase the number of rounds a revolver can hold.

What Handgun Has The Most Rounds?

To date, the handguns that can hold the most rounds from the factory are 9mm Glock models. The Glock 17 has several magazine configurations, the largest of which accommodates 33 rounds. Of course, if we’re talking about aftermarket magazines then it will vary from pistol to pistol. Although, there are 100 round drums available for Glock models (e.g. Glock 18) that can be purchased at your local gun show or online. Don’t expect to find any gun manufacturers advertising this type of magazine.

How Many Rounds Should Your Concealed Carry Have?

Now that we’ve talked about how many rounds a gun can hold, what about how many rounds should your concealed carry hold? Your concealed carry pistol should have between 6-15 round magazines. Many subcompact and compact pistols have magazines that fit this range. While I tend to carry at the higher end, ultimately it comes down to your ability to conceal your handgun.

One distinct advantage of an automatic is that you can hold additional rounds in a spare magazine. I recommend carrying a spare magazine along with your concealed pistol. Check out the 5.11 Tactical concealed carry compression shirt which has a pocket for an additional magazine. Not only does this double the amount of rounds you have access to, but it also provides another option should you experience a malfunction with your primary magazine.

Parting Shots

To sum things up, the number of rounds a pistol can hold will vary depending on a number of factors. If you’re looking to carry more rounds in your handgun, it’s best to get an automatic handgun, chambered for a smaller round. Having an automatic allows you to purchase aftermarket magazines which can hold more rounds. Revolvers and Derringer style pistols have a set number of chambers, and therefore a set number of rounds that can be loaded.

Regardless, of what option you go with, make sure you can still conceal your handgun. Do you have anything to add? Know of any other pistols that hold more than 33 rounds from the factory? Leave a comment for our readers.