The Most Modular Handguns

Estimated reading time: 8 minutes

What has kept the AR-15 around for so long? It’s been in production almost long enough for it to collect Social Security. The rifle has served our country for generations and is the most popular rifle in America. Dozens of companies produce it. Why? Because it’s modular. Modularity is what keeps a weapon around. Its ability to innovate, adapt, and evolve keeps a firearm around. We know the AR-15 is the world’s most modular rifle, but what are the most modular handguns? 

I set off to figure that out and couldn’t pick just one. The handgun world is beset by fairly modern weapons. While the AR-15 dominates the rifle industry, there isn’t necessarily one handgun design that dominates. There are several options out there, and I’ve found five that are modular, modern, and capable. 

Why Modular Handguns Matter

The AR-15 dominates because it’s capable of adapting to the modern era. Modular handguns can do the same….and, well, a bit more. Modularity allows guns to adapt to modern needs, but they can also be adapted to the needs of individual users. Handguns are typically designed for a very particular role, but a modular handgun can be adapted to numerous roles, making a single purchase so much more valuable. 

With that in mind, modularity can be a purposeful choice or a happy accident. When a gun really succeeds, it’s a bit of both. Let’s dive into the five most modular handguns out there.

Glock, Just The Whole Brand 

Glock’s modularity is the perfect example of purposeful design and a happy accident. The happy accident coming from the Glock aftermarket. You can make a Glock pistol without a single part made by Glock. Glock’s absolute dominance over the market for handguns for so many decades led to a massive and profitable aftermarket. This opened up the ability to add in new triggers, sights, magwells, magazines, barrels, and beyond. 

Additionally, the Glock series are very simple guns. They aren’t complicated, and that allows for more freedom to customize the guns at the user level.

Eventually, optics cuts and rails became standard, which also aided in modularity. Certain guns have more options than others. For example, the 10mm Glock 20 can be converted to chamber a wide variety of rounds outside of 10mm. 

Glock also embraced a degree of modularity with the release of the Glock 47 series. This gun allows you to swap slides and frames with the Glcok 19 and 17 series. It’s a slight bit of purposeful modularity that goes a long way. The aftermarket has created everything from braces to rifle conversion kits. What else could you want from an entire series of handguns? 

Go With the SIG P320 

The SIG P320 was SIG’s first really successful modular pistol. The P320 is built on the failure of the P250 and its removable chassis. Lots of companies these days have pistols with removable chassis systems, like Beretta and Springfield Armory, but SIG has been the most successful series. SIG’s own support includes affordably priced and easy-to-find grip modules, as well as slides and caliber conversions. 

The P320 has also seen a fairly large aftermarket, with grip modules and slides being produced by a ton of companies. This includes big names like Wilson Combat, as well as smaller companies like Mirzon and Amend2.

Amend2 produces a grip module that allows you to use P365 magazines in your P320. Grip modules like the Flux convert the P320 from handgun to PDW in one quick swoop. 

The P320 series has a lot going for it with its adoption as the US Military’s sidearm of choice. It’s grown into a series of handguns that offer something for everyone, from concealed carry to hunting. The modularity of the pistol makes it a must-have for tinkerers. I have five different grip modules for my P320 and a Flux Raider, so I guess I’m all in. 

Or SIG P365 

The SIG P365 followed in its big brother’s shoes. Like the P320, the P365 has a removable fire control unit. The aftermarket has made a killing by modifying and providing entirely new frames for the weapon, as well as high-tech, custom slides. The many variations of the P365 include an XL model, the Glock 19 competitor XMACRO series, as well as the SAS, the .380 ACP variant, and many more.

It’s not tough to convert your P365 into the gun you want it to be. With a rail and optics, the ability to add accessories is easy.

Much like the Glock, the popularity of the P365 has led to a massive aftermarket. It’s aided by SIG’s own compatible design, so I can throw a long slide on a short grip and vice versa. I can throw my XL slide on my XMACRO frame. Magazine capacity can even vary between ten and seventeen rounds. 

The aftermarket offers the usual triggers and optics, as well as compensators, light sources, and lasers. Most impressively, there are a number of grip modules on the aftermarket, including all metal models that are fairly impressive. Flux has been teasing a P365 Raider for quite some time as well, so maybe we’ll see that sooner or later. 

ZRODelta One: A Great Modular Handgun

ZRODelta was one of those famed Glock shops that helped press the customization of Glock forward. They have since begun producing their own firearms. The ZRODelta One used to be called the Modulus, but the name switched to represent the fact it’s the One gun you need. The idea is that the one can become any gun you need it to be while keeping the same serialized frame. 

The One uses a Universal Fire Control as the serialized component of the firearm. From there, the One can be built, without tools, into the pistol you need it to be.

The UFC is part of the grip and frame but looks oddly incomplete. That’s because the end user can extend the grip and dust cover to convert the pistol to compact, duty, or race gun-sized platforms. 

Users can take the One and add the front and back straps of their choice, as well as varying mag wells. Users can pick the railed dust covers they prefer and the slide assembly they want. They can swap the size of the frame with ease, and the slides drop in and out easily enough. Essentially, it’s a Glock in many ways, but clearly something massively different. Unsurprisingly, it allows you to make some funky-looking pistols, but who says funky isn’t good? 

Dan Wesson Switch Barrel Revolvers 

Dan Wesson revolvers are like Jonah Hill’s weight. They yo-yo back and forth. Sometimes, they are in production. Sometimes, they’re not. They are the only revolver platform I know that offers user-level customization of barrel lengths. The Dan Wesson 15 and later 715 famously use a convertible barrel system that allows the user to swap barrel lengths on demand. 

It was simple to do, and a gauge ensured the barrels were installed correctly and safely. The original Dan Wesson Model 15-2 utilized barrel lengths of 2.5, 4, 6, 8, and later 10, 12, and 15 inches. In 2018, the CZ-owned Dan Wesson brought out the 715 with 4, 6, and 8-inch barrels in 2018 to revive the brand. 

The Dan Wesson Switch Barrel revolvers aren’t exactly super modular, but I felt they deserved a mention. We know the Switch Barrel system works, but Dan Wesson seemed to be the only company ever interested in using it, and they get credit for their creativity and engineering prowess. 

Keeping it Modular 

Modular weapons tend to go far. We’ve seen three of these five have massive success. The ZRODelta is ahead of its time, and the Dan Wessons were sadly born too soon to be too popular. Modularity does seem to be the key to a firearm’s success, and handguns have embraced that wholeheartedly. These are the five most modular handguns, according to me, but maybe I’ve missed one or two. Let us know below. 

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