Is this a perfect pistol? Possibly the most enjoyable firearm I’ve ever owned, my recently-acquired SIG Sauer P320 Nitron Compact (9mm). I can’t imagine a more simple and lightweight tool. Perfect crisp, smooth, light 2-stage factory trigger. Bold high-vis sights practically lock on target. So ergonomic it fits my hand like a glove and feels like an extension of my own arm. Just effortless to pick up and use and maintain. Built for military and defence applications. Ideal for IPSC. Precise enough for paper target competitions. Perfect for plinking.

The P320 weapon platform is a striker-fired semi-auto pistol (short recoil-operated, locked-breech) with a Nitron slide and polymer frame. The P320 series is characterized by modularity and extensibility. SIG factory parts and custom upgrades and parts are widely available.

The P320 is extremely reliable. This is probably one of the key criteria upon which it was selected by the US military. I doubt you could find a more dependable pistol. When you pull the trigger, it works. There are countless torture tests demonstrating how robust this handgun is. The P320 will continue to function after being submerged in dust, sand, dirt, water, and thick mud. That includes pine needles and repeated impacts. Even if you cycle in it mud until it needs a slap to return it to battery, a quick rinse in dirty water restores normal function. That might not be a factor for plinking, but it could matter greatly when it’s life or death.

My P320 model (SKU 320C-9-B) ships with two OEM 15-round mags. SIG also makes a 10-round mag for this model, and additionally I use Magpul 17-round extended mags as well as Magpul’s 15-rounders. I also use SIG’s 21-round mags, but a fully-charged 15-round Compact mag seems the optimal balance of weight and size vs capacity. The calibre is 9mm Luger “Parabellum” (9×19 mm). The P320 Compact’s OEM grip module provides a M1913 picatinny rail beneath the muzzle for accessories (e.g. typically a lamp or laser). The P320’s Sight Picture type is Combat Hold (cover the point-of-aim) with its factory zero at 25-yards printing a 2-inch group.

The P320’s Fire Control Unit is a single self-contained component at the heart of the pistol, making it especially tidy and easy to take-down, disassemble and reassemble the gun. The serial number of a P320 is on the FCU, not the frame or barrel – an innovative strategy whereby the FCU module is officially the registered firearm in US law. Thus, everything else on the gun is an accessory. The FCU system, together with the modular design of the P320, means you can build and own different versions of the gun, all using the same serial number. You can buy a conversion kit (from SIG or many others) to change the calibre of your handgun, without changing the serial number. You could also convert it to a whole new PDW chassis.

Despite its famous modularity and extensibility and seemingly infinite aftermarket customisations, even after thousands of rounds 100.00% flawlessly fired with never a malfunction, I have not yet needed or wanted to change a single part of my own P320 Compact. This is testimony to the excellent factory specs. I prefer the feel of a curved trigger, and the OEM trigger snugly embraces the geometry of my trigger-finger. Even the OEM grip module is too comfortable to change.

The marketplace has shifted to a maximum customisation paradigm, with my legacy P320 Compact Nitron (launched in 2014) now superseded by the optics-ready but otherwise analogous P320 Compact (initial SKU 320C-9-BSSP released in 2023 where B = black Nitron finish, SS = Siglite Night Sights, and P= “Pro” slide with optic cut). The X-series represents the latest evolutionary branch of the P320, with P320 XCompact (launched in 2019) having a shorter 3.6″ barrel, flat-faced trigger, a revised grip module with trigger-guard undercut and extended beavertail, and an optics-ready slide with X-Ray3 day/night sights (see side-by-side comparison of Compact and XCompact). I appreciate the robust simplicity of my OG legacy Nitron Compact model – although, of course, an upgraded optic-ready slide with integrated SIG-LOC and XRAY3 is available for it if required. If I could not have the Nitron Compact, I would be equally satisfied with the newer optics-ready Compact. The XCompact is an equally viable and welcome alternative, its shorter barrel length does not make a significant difference to my shooting (notwithstanding on paper a 10-15 fps reduction in velocity and shorter sight radius). If I wanted a precision instrument to showcase my skill at the range, I would select a full-sized model, e.g. the hefty P320 XFive Legion with its 6.8″ sight radius for fine-tuning my aim and its 5″ match-grade barrel as well as all having that weight to absorb more muzzle-flip and recoil. You can design your own custom P320 online on the SIG website (here’s mine).

The official US military versions of the P320 pistol series are the M17 (full-size) and M18 (compact) models. The M17/M18 (P320) weapon platform is “the official sidearm of all branches of the US military” including Army, Navy, Marine Corps, Air Force, and Space Force. The official description of the M17/M18: “The Modular Handgun System (MHS) pistol is a mechanically locked, short-recoil operated 9mm pistol, featuring an automatic striker pin safety lock, ambidextrous manual safety and external ambidextrous slide catch lever.”

The P320 I used in this video was manufactured in 2024 in New Hampshire, USA (serial number 58J56xxxx) with the 2017 FCU version and exported to Europe through a military/police contract. My P320 was imported into the EU by Plus Ultra Tactical & Rescue (catalogue) where Excopesa is also a key importer for the civilian market. E.g. In Spain, a NATO member since 1982, military and security forces personnel routinely purchase personal firearms from civilian gun shops (“armerias”) with their military ID (TIM card) functioning as a Type A weapon licence. Spanish police forces and individual officers also purchase equipment and ammo from civilian firearms dealers, and Spanish police are authorized to carry their firearms while off-duty. Spain has a firearm distribution of more than 10 guns per 100 people in the population (including police who are universally armed), yet the country has one of the lowest gun fatality rates in the world, negligible at around 0.11 gun homicides per 100k people, and fatal shootings by police are estimated to average fewer than 10 per year. For reference, the island nation of Jamaica, where civilian gun ownership is banned, records 42 firearm-related homicides per 100k people, and probably many are unrecorded.

My current loadout for the shooting range:

Other reviews:

Postscript – debunking the mythical Accidental Discharge debate on P320 series pistols (especially Compact models):

Naturally, nobody wants to blame themselves, and it’s easy to blame the machine, but to cite the old maxim: “A bad workman sometimes blames his tools.”

The P320 is evidently engineered with generous fault tolerances. If there is a trade-off for being this reliable, I’ve yet to see conclusive or reproducible evidence.

Trivia: the iconic P320 featured in the Hall of Mirrors scene in a recent John Wick movie. In real life, Keanu Reeves is a proficient shooter.

2 thoughts on “SIG Sauer P320 Compact pistol: definitive review”

  1. Review – P320 takedown and modularity demo, showing how to use the P320 conversion kits to easily convert 1 firearm (1 serial number) into all the different P320 models (sootch00)

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  2. SIGLITE Night Sights

    The P320 Compact is available with SIGLITE Night Sights, as defined by the SKU/model. SIGLITE means self-illuminating iron sights that work by radioluminescence. The white dots on the sights contain glass vials filled with tritium, a radioactive isotope of hydrogen that emits low-energy beta particles. Phosphor crystals coating the glass vials is excited by the beta particles, releasing photons of visible (green) light. This makes the sights visible in low light and usable even in total darkness — as long as you can see the target, of course.

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