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Review: SIG Sauer P320 - M17

The civilian variant of the U.S. military's standard-issue duty pistol is red-dot ready.

Review: SIG Sauer P320 - M17
Photos by Alfredo Rico

SIG Sauer pistols like the P226 and P229 have long served police officers, government agencies and militaries around the world; they have even found their way into private citizens’ homes for personal defense. During this time, the SIG Sauer name has become synonymous with quality, reliability and accuracy. Now the innovative P320 continues this legacy as it rises to the forefront of today’s defensive pistol offerings.

With its unique chassis design, the pistol epitomizes modularity, enabling the user to transition between three sizes with a simple grip module swap. Since the grip modules are so affordable (starting at $39), the P320 is an economically sound alternative to purchasing three pistols.

Not Just For Soldiers

Modularity was undoubtedly a factor in SIG Sauer winning the highly-­coveted U.S. Army’s Modular Handgun System contract with the M17. Just because a pistol is well-­suited for the Army doesn’t necessarily mean it will be a good fit for private citizens, or even that it will be available to the commercial market. Fortunately for shooters, SIG Sauer has decided to release a commercial variant of the M17, dubbed the P320-­M17.

The P320-­M17 is a slightly modified version of the Army’s M17 pistol. According to SIG Sauer, the P320-­M17 “closely follows the specifications of the U.S. Army’s M17.” This includes a coyote-­tan finish with black controls and a thumb safety. I’m told the company plans to produce a version without the thumb safety as well.

SIG-M17 red-dot ready
SIG’s P320-M17 is virtually identical to the M17 adopted by the U.S. Army, including the coyote-tan finish, black controls and the chassis that enables unprecedented modularity.

Each gun ships with two, 17-­round magazines and sports a SIGLITE front night sight and a removable Night Sight rear plate. The PVD-­coated, stainless-­steel slide features the same optic cut as the M17 for the mounting of an electronic sight. The carry-­length grip module comes in three sizes (large, medium and small). All have an accessory rail for the mounting of a light or laser.

The pistol’s ambidextrous safety is a welcomed addition for left-­handed shooters (or right-­handed shooters relegated to shooting left handed). The magazine release can be positioned on either side of the pistol. These features are nice to have on any pistol but they are virtual must-­haves to stay competitive in today’s duty and defensive-pistol markets.

Aggressive front and rear slide serrations provide a solid grip regardless of the technique you prefer to cycle the slide. The textured grip panels help to keep the pistol firmly in your hands when firing. The magazine release is just the right size and is also textured to ensure your thumb doesn’t slide off when ejecting a magazine. I found the controls on the P320-­M17 to be both well-­situated and well-­executed.


Disassembly of the P320-­M17 is easy and does not require you to press the trigger, which is a valuable safety feature. Obviously, you should always know the condition of your pistol and always verify the pistol is unloaded before disassembly, but I’ve known very experienced shooters who, in a moment of distraction, have shot themselves this way.

To disassemble the P320-­M17, simply lock the slide to the rear, rotate the takedown lever counter­clockwise 90 degrees, then pull the slide forward. Remove the takedown lever from the grip module and pull the chassis upward and forward to remove it from the grip module. This procedure can be done to conduct a detailed cleaning of the trigger assembly or to swap the serialized chassis into a different grip module as appropriate.

SIG-M17 red-dot ready
Modularity is the key to the P320-M17’s success. The rear sight plate is removable to mount a red-dot optic. Also shown here are the slide’s internal components.

The test sample I was sent came with a SIG Sauer ruggedized Romeo1T prototype red dot that was mounted after removing the rear sight plate. While not a daunting task, the baseplate and internal components had to be removed from the slide to secure the red dot in place using the supplied Allen screws.

Letting It Run

To sight in the red dot, I fired several shots from 7 yards. Windage and elevation were adjusted with a standard screwdriver without issue. These warm-­up shots allowed my trigger finger and me to acquaint myself to the intuitive P320 controls.

SIG-M17 red-dot ready
Red-dot optics like this SIG ruggedized Romeo1T simplify the aiming process, eliminating the need to change your focus from the threat to your pistol’s sights and back again.

After zeroing, I pulled up a chair and braced the pistol on a sandbag. I placed the red dot smack dab in the middle of the 25-­yard bullseye target and let ’er rip. First up was Federal’s Hydra Shok Deep, a 135-­grain JHP round designed to achieve deep penetration for optimal terminal ballistic performance. The round produced predictable results with group sizes ranging from 2.48 to 3.03 inches, with a group average of 2.74 inches.

The indoor range I was shooting in was somewhat dimly lit, which can make using traditional sights problematic. With the red dot, however, I was able to clearly see my aiming point and was able to acquire the sight much faster, resulting in faster strings of fire.

I was impressed with the trigger, which featured a flat, relatively wide face and a smooth press. I found the pad of my finger conforming nicely to the curvature of the trigger. Despite the trigger measuring 8 pounds, it felt much lighter. The P320-­M17’s trigger will assuredly be the envy of many competitors.

SIG-M17 red-dot ready

As expected, recoil felt a little snappier with SIG Sauer’s V-­Crown 115-­grain JHP but was still of little consequence. This load printed tighter groups, measuring its best group at 1.53 inches and averaging 2.11 inches, which was skewed by a 3.17-­inch group.

Hornady’s 135-­grain Critical Duty, with its unique XTP design, fared pretty well, too. Groups ranged from 2.36 to 2.99 inches. However, the heavier 147-­grain Hornady Custom XTP outperformed the others. Hornady Custom registered not only the best group of the day at 1.3 inches, but also had the best overall group average at 1.62 inches.

I tried to throw the P320-­M17 a curveball with the very light Winchester 90-­grain Super Clean Zinc Core FMJ. Aside from a flyer-­induced 5.13-­inch group, the pistol produced groups ranging from 2.35 to 3.35 inches. While these groupings didn’t exactly hit the curve ball out of the park, they delivered a solid base hit.

Accuracy results notwithstanding, the P320-­M17 is not designed to be fired slowly from a benchrest. Whether protecting our soldiers overseas, our police officers on patrol or a citizen who unexpectedly crosses paths with a criminal, this pistol was bred for combat.

It’s important to note that with at least 250 rounds fired, the P320-­M17 didn’t skip a beat until the very last round fired through the chronograph, which was a failure to feed using the 90-­grain Winchester load. Perhaps the round was a little too light to facilitate optimal slide reciprocation. When loaded with premium defensive ammunition, this pistol is a force to be reckoned with. I expected nothing less from SIG Sauer.

SIG-M17 red-dot ready

Rarely has a pistol felt as good in my hands or performed as well as the P320-­M17. It proved to be accurate, reliable and comfortable to shoot. With grip module options, the pistol can be tailored to your ever-­changing needs. I can envision carrying the full-­sized version on duty, then transitioning to a smaller grip module for concealed carry.

I know far too many police officers who practice with and carry a full-­sized pistol on duty then leave it in their locker only to arm themselves with a pocket pistol or snub-­nosed revolver, which is certainly easier to carry but far more difficult to shoot. With the P320-­M17, one pistol with an extra grip frame is all you need.

Of course, the benefit here is that since you are using the same pistol, the trigger pull, sights and controls are identical regardless of the grip module. This commonality of use is critically important considering how well you run your gun could be the difference between life and death.

Having been a police officer for over two decades, I would carry the P320-­M17 in an on-­ or off-­duty capacity without reservation. If you’re in need of a pistol to bet your life on, look no further than the pistol that won over the U.S. Army.

SIG-M17 red-dot ready
Accuracy results are the average of five five- shot groups from a benchrest at 25 yards. Velocity figures are derived from a string of five rounds measured by a chronograph 12 feet from the muzzle.

SIG Sauer P320-M17

  • Type: Striker-fired semiautomatic
  • Cartridge: 9mm Luger
  • Capacity: 17+1 rds.
  • Barrel: 4.7 in.
  • Overall Length: 8 in.
  • Weight: 1 lb., 13.6 oz.
  • Height: 5.5 in.
  • Width: 1.3 in.
  • Grip: Coyote-tan grip module
  • Finish: Coyote-tan, PVD coated stainless steel slide
  • Trigger: 8 lbs. (tested)
  • Sights: SIGLITE front; removable Night Sight rear plate
  • Safety: No manual safety; MS version has one
  • MSRP: $768
  • Manufacturer: SIG Sauer;

Red Dot

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