Adaptive Striker-fired Greatness: The SIG P320 Pistol


In my not-so-humble opinion, SIG Sauer makes some of the finest handguns on the planet. My go-to home defense pistol is a 9x19mm SIG P226 with a 20-round magazine, and my carry gun is a P938. However, my competition pistol has always been a lightly-modified 9x19mm Glock 17. For whatever reason, I shoot Glocks more accurately and faster than any hammer-fired handgun.

For years I wished SIG would release a striker-fired pistol that combined the SIG reputation for quality with a compact, concealable frame. I sought something that would replace both my competition and carry guns, allowing me to transfer skills learned in competition to my carry piece. Kind of like a Glock 17 that could transform into a Glock 26 in a matter of seconds. Enter the SIG P320 system.

Yes, I said system.

The P320 is the next evolution of the modular P250 handgun platform. The P250 consisted of a serialized fire-control unit containing the trigger, sear, and hammer assemblies. Both handguns use interchangeable polymer frames to allow shooters to customize the pistols to suit their needs. In fact, the only difference between the two is manner in which they detonate rounds—the P250 is hammer-fired, whereas the newer P320 is striker-fired.

This is important, because most modern police agencies are run by bureaucrats who fear single-action triggers. They’re often left with two choices: double-action-only, hammer-fired guns or striker-fired pistols. Accurate, fast shooting can be accomplished with DAO pistols, but if Jerry Miculek is any indication, it requires a great deal of training. Striker-fired guns are easier to train novices on because of their simplified controls and lighter triggers.

I had a chance to fire a friend’s P250 in .357 SIG, and while it comfortable and reliable, the double action only (DAO) trigger was too long and heavy for me to consider for competition. It’s not terrible, and shooters can easily fire respectable groups with it. However, it doesn’t lend itself to the rapid, accurate shooting necessary to succeed in competitive shooting matches.

Truthfully, I had all but forgotten about the P250 when a SIG Sauer representative handed me a P320 during a factory tour. Initially I dismissed the pistol as simply a differently-profiled SIG P250 until I had a chance to get some trigger time with the 9x19mm version of it later that afternoon. The ergonomics were better than I remembered, and the trigger pull was consistent and light with a crisp, clean break. Was I looking at my next competition pistol? I put the SIG to the test to see how it fared against my old workhorse, a third-generation Glock 17.

Both the Glock 17 and the SIG feed from a 17-round magazine, are striker-fired, and utilize a polymer frame. Capacity and operating methods being equal, where these pistols differ in ergonomics, versatility, and aftermarket support.

User-friendliness has never been the strong suit of Austria’s famous polymer pistols. They’ve always embraced a spartan approach to firearms design, believing form follows function. Newer iterations of the Gaston’s pistols have improved upon their predecessors’ ergonomics, but they’re still nothing to write home about. This is the one area in particular where the SIG P320 utterly destroys the Glock.

The serialized fire-control unit is the official "gun" part of the P320. You can swap barrels and frames at will without having to deal with an FFL transfer.
The serialized fire-control unit is the official “gun” part of the P320. You can swap barrels and frames at will without having to deal with an FFL transfer.

The grip on the SIG would be the OSHA standard if they applied to pistol grips. It has texture where it needs it and matte smoothness around the trigger, allowing the shooter’s hands to naturally find the trigger.

This leads us to versatility. The grip is available in three variations for all three frame sizes, resulting in nine possible configurations of the pistol. Frames tested for this review included all grip-size variations of the full-sized (with 4.7-inch barrel) and compact (with 3.9-inch barrel) frames.

Since the fire-control unit is the serialized part of the P320, shooter’s can purchase a single pistol and then order additional frames and slides to change everything from grip size and magazine capacity to barrel length and caliber—all without having to deal with an FFL. Think of it like having the modularity of the AR-15 in a handgun.

All versions of the gun are short recoil-operated, locked-breech semiautomatics and feed from the same type of magazine. Like the Glock series of handguns, smaller models can use magazines from larger models, but not the other way around. The full and compact-sized P320s sport identical magazine capacities as the Glock 17 and 19 respectively, though the sub-compact P320 holds two more rounds than the Glock 26’s 10-round, flush-fitting magazine.

Full-sized and compact P320 frames feature Picatinny accessory rails.
Full-sized and compact P320 frames feature Picatinny accessory rails.

Both the full-sized and compact models include a railed dust cover for mounting lights, lasers, or other accessories, the subcompact model does not. Anyone who has ever carried a gun with a rail knows exactly why. The recoil grooves of accessory rails love clothing and soft holsters. Anything they can get their abrasive teeth into, they will. This is doubly true when a shooter desperately needs to employ a weapon from concealment.

Clearly SIG realized this and designed accordingly, though this isn’t the only sign SIG designed the gun for serious use. It also includes phosphorescent night sights to aid in target acquisition under less-than-ideal lighting conditions and aggressive grip-stippling. The latter aids in weapon retention. Easy to shoot, easy to aim, easy to control, and hard to drop. What else do carry guns and competition pistols need?

Impeccable accuracy and reliability.

Since this gun must pull double duty as a carry piece and 3-gun pistol, I decided it made sense to test it not just with carry ammo, but also plinking rounds. For carry ammo I chose my three favorite 9x19mm hollow points: SIG’s 124-grain JHP, HPR BlackOps 85-grain open tip frangible, and my old favorite, Federal 124-grain Hydra-Shok JHP.

The P320 yielded impressive shot groups and impeccable reliability. The only failure the author encountered while shooting the P320 was due to an ammunition issue.
The P320 yielded impressive shot groups and impeccable reliability. The only failure the author encountered while shooting the P320 was due to an ammunition issue.

Defensive ammo is expensive, so I limited testing to 40 rounds of each after firing a few hundred rounds of plinking FMJ first. This was done to simulate both extensive use and shooters who forget to clean their carry pieces after practice.

Fired unsupported while standing at 15 yards, five-shot groups using an extended, threaded barrel with the compact frame were measured and averaged. My go-to carry ammo from Federal performed admirably, grouping 2.1 inches at 15 yards, while the soft-shooting HPR grouped slightly worse, averaging 2.23 inches. The real belle of the ball was SIG’s own Elite Performance round, which achieved 1.66-inch groups. Given the average distance defensive shooting take place at, all of these are more than accurate enough.

For plinking ammo, I used Winchester NATO-spec 124-grain FMJ, Wolf 115-grain FMJ, and Romanian Hot-Shot 115-grain FMJ. Both Wolf and Hot Shot grouped around 2.4 inches, while the heavier Winchester ammo achieved 2.2-inch groups.

All variations of the P320 tested were left unlubricated for the duration of the test, and were only cleaned at the end for photographs. Across 400 rounds of ammo tested, only a single malfunction occurred. A single round of Hot Shot failed to detonate. After pulling the round, my assistant and I determined the primer had nothing in it.

Retailing for $669, the SIG P320 is a very attractive alternative to offerings from Smith & Wesson and Glock—especially with its great ergonomics, solid trigger pull, and attractive styling. The P320 won’t appeal to shooters who are heavily invested in other striker-fired guns, especially if they already own multiple sizes of the same model. That said, the P320 is the ideal gun for someone looking to purchase both a concealed-carry piece and a competition gun, and share magazines and accessories among them.

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