What makes the SIG Sauer M17 and M18 so special? In 2017, it was announced that SIG Sauer won the modular handgun competition. The military had spent a lot of time and way too much money deciding which handgun to issue next. The Beretta M9 would be replaced by the winner of the Modular Handgun System. Beyond the Beretta, the military also wanted to replace the General Officer M11 and M9 gun. As such, the modular handgun would actually be two guns, and that’s how the M17/M18 was developed. CZ, Beretta, Smith and Wesson, FN Herstal, Glock, Kriss USA and STI were all beaten by SIG Sauer.
The M17/M18 series would replace three barrels in total and modernize the army’s handgun choice. After the Army declared the M17/M18 the winner, it was slowly announced that the Navy, Air Force, and Marine Corps would also adopt the M17/M18 series. The modular handgun was a winner, but what made it so modular? Today we’re going to explore what modularity means in general and how it applies to a handgun specifically.
The military has learned that modularity is important. The success of the M4 is directly linked to its modularity and ability to be customized for mission specific use. The MHS aimed to bring this customization to the M17/M18. Today I don’t have an official M17/M18, but I have a P320, which became the M17 and M18 handguns. Although not a direct comparison, my P320 will illustrate the modular handgun.
The heart of the U17/U18 – The FCU
Modularity is important because not all missions and tasks are the same. The military must consider different environments, jobs, tasks and missions. The infantryman has different requirements than the human-intelligent (HUMINT) soldier or navy.
An infantryman works best with a full-size combat handgun, potentially equipped with a weapon-mounted light, 21-round magazine, and red dot optics. The HUMINT guy or girl may need to conceal a pistol, so they want a smaller gun without the optics, light, and 21 round magazine. The M17 and M18 provide a full size model and a transport model respectively.
They are effectively the same weapon, just different sizes. This decreases training requirements by simplifying the weapons manual.
At the same time, the logistics are improved and simplified between the two roles and the different weapons.
Inside the M17/M18 series is what SIG calls a fire control unit. All parts, apart from the version of the magazine that rocks the P320, are part of the FCU. The FCU is the serialized part of the weapon and is considered the actual “firearm” by law. This allows internal components to be inserted and removed from the gun for easy maintenance and also allows for extreme modularity.
The FCU can be replaced with different grip modules and can be adapted to different slide sizes to enlarge or reduce the size of the gun. My P320 has a compact gripper module, a full-size all-metal gripper module, and a spare S300 subcompact gripper module. I can quickly switch between weapon sizes for different tasks. The same goes for the M17/M18 pistols.
M17/M18 beyond the FCU
Beyond the ability to swap slides and grip modules, the M17/M18 offers a wide variety of customization options. First, the Picatinny rail allows you to attach lights and other accessories. This includes IR lasers for night vision. The top of the optic is cut for one; although optics on handguns look silly, wait until you use one.
These mini red dots make your gun easier to shoot in every way. You can shoot faster, further and more accurately. The red dots can help with the challenge of pistol shooting and will make the soldier armed with a handgun more deadly.
The MHS contest also called for the ability to mount suppressors. Suppressors are gaining more acceptance in the military world and could be important for special ops dudes doing sneaky things in the wrong places. The M17/M18 allows the user to swap sights on demand, which the M9 and M1911 simply couldn’t do.
Long term use
Modular weapons often stick around longer than less modular designs. If you can constantly and easily upgrade a weapon, why get rid of it? We saw this line of thinking with the M4 and M16 rifles. This same future could exist for the M17/M18 handguns.
Although not yet on the table, the M17/M18 can be easily modified by the US military as they see fit. In the future, we may see grip modules with built-in light or IR lasers, and we may see smaller or larger systems depending on user needs.
SIG began developing a very short, lightweight suppressor that is an integral part of a P320 slide. This would allow a gun suppressed by general forces to be easily stored and transported. Companies like Flux Defense have produced kits that turn the P320 into a short, lightweight carbine by adding a stock and foregrip to the design.
As the P320 grows in popularity, we are likely to see a wide variety of upgrades, modifications, and additions to this handgun. When appropriate and necessary, they could be adopted by the military en masse or in small numbers for special units and tasks.
The M17/M18 series of handguns are likely to live a long life and see continuous improvements. At this point they represent a very modern option on par with any modern handgun. Yet they offer a superior level of modularity that will likely keep them in service until we decide on a new caliber.
Travis Pike is a retired Marine Gunner who served with the 2nd Bn 2nd Marines for 5 years. He deployed in 2009 to Afghanistan and again in 2011 with the 22nd MEU (SOC) during a record 11 months at sea. He trained with the Romanian Army, Spanish Marines, Marines of the emirate and the Afghan national army. He is an NRA Certified Pistol Instructor and teaches concealed carry courses.