Concealed Carry & Home Defense

Gun Test: Sig Sauer P320

Guns and Gear Contributor
Font Size:

By John Connor, GUNS Magazine

I’m rarely accused of being sharp, so I’ll be blunt. (I’m good at that.) I’ve happily shot the snot outta the new SIG SAUER P320—to the tune of about 1,200 rounds and counting now—and here are the bullets:

First, this is a sweet, sweet shooter; strong, simple, comfortable, safe, accurate and reliable. Second, it may not be truly “ground-breaking,” because the SIG P250 already broke the modular, multi-caliber, shape-shifting size-changing ground some years ago, but the P320 has taken the concept and not just kicked it up a stair, but booted it all the way up to the next landing on the modular-morphing-mutant staircase.

I know. Professional gunwriters aren’t supposed to spill the beans right outta the gate. Readers are supposed to be spoon-fed tantalizing tidbits as the music builds to a crescendo of conclusions. But I’m not a PGW, and this is how IWO’s—Itinerant Weapons Operators—do it when you find a pistol like the P320; one you can take from the box, ensure there are no accidental bore obstructions, check for proper light lube, load up mags and commence shooting several hundred rounds with complete comfort and growing affection.

There’s no “break-in”—it’s good-to-go out of the box. It doesn’t “settle down” because it’s already settled. The trigger pull doesn’t change, nor do the excellent sights have to “grow on you.” You just get better, faster and more confident with it. With a 10-second reading of instructions, you’ve mastered every important aspect of operation and fieldstripping. In another 20 seconds reading you can tear it down to the level a unit armorer would. You can change the grip ergonomics with an inexpensive, simple swap and take it from full duty-size to compact or sub-compact size and legally still have only one “firearm.” Hyperbole? Bold talk? Nope. Just straight talk.


Fixed Siglite tritium-powered night sights are optional on the P320. The front sight is drift adjustable for windage (left) as is the rear. The sight radius is 6.6 inches. Note the slide stop just below the beginning of the slide serrations.


The P320 has a generous ejection port lower on the right. Note the window on the frame. Inside the window is the serial number on the module of the fire system. It allows the P320 to be converted easily into a carry or compact version.


The takedown lever operates only when the slide is pulled back—allowing you to verify the pistol is unloaded. It depresses the striker bar on activation meaning there is no pulling of the trigger to begin disassembly.

The design concept is stunning in its simplicity. On the topside, you have a more or less conventional slide, recoil spring with captured guide and barrel. What in other pistols would be called the “frame” and constitute the serial-numbered “firearm” is, in this design, the grip module. It is a featherweight but tough polymer component which, aside from the magazine catch, has no pinned-in or pressed-in “action things & springs,” widgets and sprockets; not even metal rails to mate with the slide.

The entire fire control works including the trigger are contained within a single, slab-sided stainless steel modular unit not unlike a cassette-type, drop-in replacement trigger for an AR, but thankfully, far easier to remove and replace. With the slide removed, the user simply rotates the takedown lever while pulling it out, then lifts the fire control unit, which SIG calls the “frame assembly,” up and out. Lift it, tip it, juggle it. Nothing falls or pops out. It’s unitized, with all parts captured. If you enjoy searching for teensy parts under your workbench, you’ll have to get ’em from another pistol.

That’s it, folks. You can change grip ergonomics, calibers and conformation from full “duty-size” to compact to sub-compact using a single fire control unit/ frame assembly. The serial number is on this assembly, by the way, and shows through a window in the grip module.

When the P320’s full panoply has rolled out you’ll be able to jump from 9mm to .357 SIG to .40 S&W to .45 ACP, with small, medium and large grip modules to choose from in full (duty) size, another three in Carry size, and three more in Subcompact, including standard smooth, tabbed or “short” triggers, and plain or threaded barrels. Looks like the old LE problem of standardizing sidearm systems for uniformed patrol, plainclothes/investigations, off-duty and undercover, and fitting petite, delicate digits to ponderous paws can now be solved with a 1-stop shopping trip at SIG SAUER. Hey, you might like that kinda flexibility too, huh? Fancy that…


SIG SAUER’s take on the striker-fired DAO is a gem for many reasons, most of which are “under the hood.” The inclusion of a 5-slot Picatinny rail is a plus. The knife is a Columbia River Knife & Tool Burnley Obake.


The P320 is a mechanically-locked, short-recoil-operated, double-action-only pistol, and SIG’s only striker-fired design since the 1930’s. Like SIG’s first foray into Gene Stoner’s AR design, the SIG516, it looks like SIG has taken the original concept, strengthened or eliminated its weaknesses and incorporated innovative new details. Obviously aimed at the law enforcement market, the P320 does not require pulling the trigger at any point in fieldstripping; it can’t be stripped without locking the slide to the rear, which ejects chambered rounds and provides a clear view and finger-check of the chamber. Safety mechanisms prevent discharge with the magazine removed and when the arm is even slightly out of battery. Those features alone could eliminate about half of all accidental pistol discharges suffered by LE agencies. Their liability lawyers will love that—and officers will love the way she handles and shoots.

The first wave of P320’s from the factory—and our test sample—are all full-size, with medium-contour grip modules, chambered in 9mm. Topside on the black Nitron-coated stainless steel slide are drift-adjustable SIGLITE tritium-illuminated sights and deep, angled slide grooves front and rear. The slide travel is notably smooth and even throughout its cycle. The ejection port is capacious and cut so it’s angled rearward on the lower right to prevent any problems with kickin’ out empty cases. At the rear of the slide a well-fitted plate helps seal the innards from dirt and debris. The slide is just 1.06 inches wide.

The grip module tells me SIG has done another superb job of “human engineering.” There’s just enough upswept beavertail to snug the web of your master hand right and tight under it without becoming an impediment. Four sections of the grip are nicely rough-textured, with coarser texturing on the front and back straps, and finer texturing on the side panels. It sits very solidly in the hand and grip is sure and certain.

As noted, our sample sports the medium dimensioned grip of the full-sized pistol, and the geometry is almost perfect for me. It makes me anxious to try the “large” variant of the carry grip module. At its widest point front to back the butt is 2.0 inches, thickness side-to-side is 1.33 inches and butt girth, measured rough with a fabric tape, is 5.6 inches. The trigger “reach,” from where the web of your hand meets the underside of the beavertail, to the front surface of the trigger, is 2.7 inches—pretty short, and it should accommodate even smaller hands. Compare those dimensions to the grip of a pistol you already like.


The slide is sculpted for easy holstering and features fore-and-aft slide serrations.


The smooth, wide trigger gives the illusion the pull itself is lighter than the scale says.


The grip is rough-textured with coarser texturing on the front and back straps.

Note the recesses on both sides of the bottom of the butt. Our magazines dropped free every time, but if you have MBDS interference—Mud, Blood, Dirt and Sand—jamming a mag, they provide an easy “pinch” grip on the mag base plate so you can rip it free. The magazine release is reversible and well placed. There is a full 5-slot Picatinny rail to mount even the largest accessories, and there’s even a small oval slot at the bottom rear of the grip if you wish to attach a lanyard. The only other widgets on the sides are low-profile ambidextrous slide locks and the nicely contoured takedown lever. I found the rear of the takedown lever makes a great positioning and stop-point for my support-hand thumb when shooting 2-handed.

The triggerguard is very generously sized, providing over an inch in height and 1.25 inches in length between the forward inner surface and the face of the trigger; plenty of room for thick and even gloved fingers. Magazines are typical SIG highest quality, Italian-made, seamless, strong and smooth, with easily removable base pads. In 9mm, the full-size mags hold 17 rounds, the Carry holds 15, and the Subcompact holds 12.

Next page please…

The trigger is an absolute treat. If you’ve never liked the feel or travel of the typically segmented multi-part triggers on striker-fired polymer pistols, you owe it to yourself to try it. Our test sample, like virtually all the first-run P320’s, is equipped with the “standard” smooth, 1-piece trigger, and I recommend it. In my opinion it’s the best off-the-shelf production DAO trigger I’ve encountered on a striker-fired pistol and very nearly as good as some high-dollar aftermarket triggers I’ve tested.


A relatively high bore axis could mean excess muzzle flip—but doesn’t. Slide is back in full recoil, with empty brass emerging (above). Muzzle flip was minimal. A split second later, with the empty cartridge flying, the muzzle is right back on target.


The trigger is a tale of quarter inches: Take-up is 1/4-inch, travel under pressure to the break is the same. Re-set is crisp, tactile and audible, and measures—taking any guesses?—1/4-inch. The trigger pull weight, measured on a Lyman electronic gauge, is a tad over 7 pounds but feels much lighter, no doubt due to the smooth trigger’s width. If you’re a fan of controlled, accurate rapid-fire, the P320’s performance is right up there with fine-tuned single-action pistols.

Firing the P320 was almost anticlimactic. I don’t think that’s the right word though, because ain’t nothin’ “anti” about it. She shot exactly as you would expect from the run-up, without a choke, cough or stutter from round one through 1,200; pointing and presenting beautifully, behaving superbly under recoil and delivering almost boringly accurate performance. Some of the first fumbles I look for in a new high-capacity pistol is failing to completely feed the first round up from a fully loaded mag after the round “up the pipe” is launched, and double-feeding when you’ve shot down to the next-to-last round. Never happened.

Firing with the pistol canted at 12, 3, 6 and 9 o’clock and at steep angles didn’t faze her, nor did shooting mixed types of ammo in the same magazine. The P320 is as good at focused aimed single shots as it is at rapid doubles and groups.

We shot two flavors of premium defensive ammo for record: the new SIG Elite Performance 124-grain “V-Crown” JHP’s, and Federal Premium Personal Defense 135-grain “Hydra-Shok” JHP’s. Both are excellent choices for carry and home defense, featuring rapid expansion, low flash, and minimal ricochet hazard. They both grouped tight and functioned flawlessly. When your average of 5-shot groups, 2-handed at 15 yards is under 2 inches, that says it all. In addition to the defensive ammo, we put hundreds of rounds of Winchester “white box” 147-grain flatpoint target FMJ’s and remanufactured 115- and 124-grain ball through her with no complaints.

The P320 was so pleasant to shoot we decided we had to give it a “high-volume fire test.” This consists of setting up some Osama Bin Zombie and Jingles the Zombie Clown targets at 10 yards, loading mags to the max and unloadin’ ’em on-target as fast as we could pull the trigger. It was tough, yeah, but somebody had to do it. She got hot—and kept runnin’ like a Swiss watch.


Searching for negative comments and caveats was fairly fruitless. I don’t need the grooved, slightly inset front surface of the triggerguard to perch my support-hand index finger on. I don’t use that technique, and don’t know anyone who does. Is it a problem? Well, no. My sole caveat is, with a mag in and a round chambered, the only thing between silence and bang! is your trained trigger finger. It would take some enthusiastic mishandling to touch off a round, but I don’t recommend using a soft fabric holster or dumping this pistol in a pocket or loose in a bag if it’s in a state of readiness. That said, I think due to the excellent trigger and recoil characteristics it’s a great pistol to teach a novice on.

Back in 2007 when the P250 was introduced, I thought “I’m looking at the future of fighting pistol design.” I bought two, both 15-round Compacts in 9mm, one with the “short” trigger, one with a threaded barrel and a dozen magazines. The P250 is hammer-fired, with a longish, very smooth revolver-like trigger. They have never been out of my “ready rotation.” In my opinion the under-appreciated P250 is one of the top 10 fighting pistol designs of the past 50 years. Another is the SIG P220 Combat .45, for its sheer Doomsday Gun survivability. Now I think SIG has a third on that short list. Connor OUT

18 Industrial Drive, Exeter, NH 03833
(603) 772-2302

Action: Locked breech, striker-fired DAO semi-auto
Caliber: 9mm
Overall length: 8.0 inches
Overall height: 5.5 inches
Overall width: 1.4 inches
Barrel length: 4.7 inches
Weight w/mag: 29.4 ounces
Mag capacity: 17 rounds
Sights: SIGLITE Night Sights
Grips: Interchangeable polymer
Slide finish: Nitron
Accessory rail: Picatinny 5-slot
Holster: Paddle-type OWB included
Price: $713


9mm Factory Ammo Performance


Load Velocity Best Group Average Group
(brand, bullet type, weight) (fps) (inches) (inches)
SIG Elite 124 1,154 1.25 1.437
Federal Personal Defense 135 1,089 1.125 1.5

Notes: Group size the product of 5-shots at 15 yards, 2-hand hold. Chronograph Data: Competition Electronics Pro Chrono Digital 10 feet from muzzle.





Legos for grownups! With the full-sized P320 slide and barrel at top for size comparison, here’s the Carry slide below it, a threaded barrel, the “medium” grip
module, Carry magazine and the frame assembly.


Christmas In August?

I had just wrapped up the story on the full-size P320 when a box arrived from SIG SAUER. The note inside said something like “We have very few of these, so please return ASAP.” There was more, but I was busy digging in. The surprise package contained a P320 Carry-size slide and barrel, a matching threaded barrel, the small, medium and large Carry-size grip modules and two 15-round Carry magazines. Was I drooling? Sorry.

I don’t think of myself as a “toy guy,” or even as a gearhead, but—this is like Legos for grownups! I stripped the frame assembly/fire control unit out of the big duty P320, installed it in the “medium” size Carry grip module and slipped the Carry slide and barrel assembly on in about the same time it took you to read this sentence.

Oh, yeah—it’s nice. Not a midget by comparison, the Carry is 3 ounces lighter, about an inch shorter overall and a tad shorter in height, but still has a respectable 3.9-inch barrel and carries 15 rounds of Fight-Stopper on board. Besides the obvious dimensions, the only difference I see is the Carry has a dual rather than single captured recoil spring, to better manage the lighter slide mass and shorter action cycle. So, the Carry P320 is simply more agile and better suited for, well… carry.

The Full Size would be my choice for IDPA, instruction, general range use and bedside security service. The Carry seems perfect for socially-serious “out & about” encounters. I’ll be shooting it as soon as I break the chains to this keyboard.

The other grip modules for the full-size P320 and the whole lineup of Carry size gear—plus the other calibers for both—should be available by the time you read this. After that, watch for the Subcompact! Enjoy the buffet!

Thanks to the Team at GUNS Magazine. Take a moment to visit their site – click here. To get GUNS Magazine delivered to your door – click here.