Gun Review: Inside The Sig Sauer P320X Compact

Gun Review: Inside The Sig Sauer P320X Compact
The slide holds a beefy extractor, and the chassis has the serial number (here, visible though a cutout in the shell).
Sig Sauer P320x 2
The Sig P320X Compact is just that: compact. And yet, it holds plenty of emergency-handling ammunition.

It's shrunk down, but the Sig Sauer P320X Compact is still large on features and performance.

How The P320X Compact Edges Out Others In Its Class:

  • Slide is machined from a billet of stainless steel and is more than robust enough to support the 3.6-inch barrel.
  • Straight bar trigger breaks when it's perpendicular to the axis, reducing overtravel.
  • Optics-ready slide, compatible with Sig Romeo1 Pro and Deltapoint Pro red-dot optics.
  • Self-contained chassis allows users to switch frame sizes.
  • Beveled mag well to expedite reloads.
  • 15+1 capacity gives user full-sized firepower in a compact package.

Some people—and companies—just can’t leave well enough alone. Mostly, that’s a bad thing, but there are always exceptions … and Sig is one of them.

The basic P320—Sig’s evolved pistol—now with a striker-firing system, has gone from strength to strength. The good parts of the P320 are still there in the P320X Compact.

The Good Parts

The slide is machined from a billet of stainless steel and, for the Compact, is made short enough to meet the demands of the barrel, which is slightly more than 3½ inches long. It gets the same sculpting as the original, with angled flats on the slide to make it easier to draw and re-holster. There are cocking serrations fore and aft, and the barrel locks up in the slide by using the ejection port. So, there are no internal locking lugs to machine or keep clean.

Raise Your Sig Sauer IQ

On top, the P320X Compact gets a set of tritium night sights—entirely appropriate for a pistol meant as a daily-carry tool. The front rides in a transverse dovetail, so it can be adjusted left to right if you need some fine-tuning for point of impact.

Sig Sauer P320x 3
The P320 is a striker-fired pistol … and the evolution of the Sig designs.

The rear is different: It incorporates a mounting plate cover. If you wish, you can remove the rear plate and mount a red-dot optic. The P320X Compact is set up to accept the Sig Romeo1 Pro or the Deltapoint Pro without a problem. I have no doubt that a competent pistolsmith could make any other red-dot optic work as well, but of course, Sig is not responsible for extra work you have done to your firearm.

The barrel is a Sig barrel made of carbon steel, rifled to allow use of hard-cast lead bullets (unlike some striker-fired pistols) and heat-treated for maximum durability. It locks up with an angled can underneath, and the hood and front of the chamber lock into the ejection port opening on the slide. Next to it is a beefy extractor.

On the frame, Sig took details from the X-Series competition line and adapted them to the EDC world. The trigger is a straight bar with a small lip on the bottom as a tactical index point. The trigger is designed so that it releases the strike when the trigger face is perpendicular to the axis of the bore.

Why? Simple: If your trigger finger is pulled directly to the rear at the moment the striker is released, the force of that pull is minimized as accuracy-robbing overtravel. When you release the striker, your finger keeps going backward. It has to—the mechanism has to have overtravel in order to work. The direction and force of that overtravel can have a bad effect on accuracy. This geometry reduces the overtravel effect and allows you greater leeway in learning to press and still hit.

Sig Sauer P320x 6
The standard P320 Compact magazine holds 15 rounds, but you can use higher-capacity magazines as well.

Sig sculpted the rear of the frame shell to allow your hand a more comfortable, and higher, carry, with an extended beavertail. Not that the original was not good, but because it is a shell, they can do more. Also, the frontstrap at the trigger guard was given an undercut to let your hand get higher on the frame.

The frame, for those who have not been keeping up, is merely a shell. Inside the frame, Sig has designed the P320 to be a self-contained chassis. It is a simple thing to remove the disassembly lever (once the pistol is apart) and then lift the chassis out.

Bigger Frame? No Problem

If you want to have a bigger frame for your carry gun, the shells are not controlled items (no serial number), and you can swap back and forth if you want. The serial number is on the chassis, and you can see it by means of a cutout section of the shell, made for just that purpose. The shells also come in larger dimensions—as in small, medium and large—if you want compact but you want larger diameter for larger hands. The marking is on the backstrap just above the hole for your lanyard loop attachment.

You can also remove the chassis from the shell before you toss everything into an ultrasonic cleaner. You might do this if you and your pistol took a spill into a particularly soupy swamp or had to wade into seawater. Getting it clean is easier than on standard designs.

Sig Sauer P320x 4
The chassis, inside the shell, is a robust steel assembly.

Let’s keep the shell-and-chassis design aspect a secret just between us, shall we? If some of the more-moronic legislators—say, from the Worker’s Paradise of Kaliforniastan—get wind of this, they might think it is some evil plot. No, it is just a way to make your Sig better suit you.

Added Features

As an added feature, the Sig designers beveled the inside of the magazine well to make reloads smoother. They didn’t go outside the shell dimensions, as one might on a competition gun, but the effect is the same, if not as absurdly marked as some competition guns can be.
Out on front, for them that wants it, there is a 1913 rail, where you can mount a light, laser or combo unit.

Magazines and Ammo

The P320X Compact, despite holding “only” 15 rounds in the magazine, will function just fine with the standard magazines, holding 17 rounds, or the extended magazines designed for the M17 military pistol, which hold 21. Of course, having these magazines in place while you are carrying will, to a certain extent, negate the concealability of the P320X Compact, so keep those handy as reloads. If you want to be ready, 15-plus on in the gun, along with a pair of 17-round standard P320 magazines, will have you packing a full box of 9mm ammo (well, an old-school 50-round box).

What kind of 9mm ammo? Whatever you want. The P320 is rated for +P ammo, and the P320X Compact is probably going to handle a steady diet of +P ammo better than you are (the 9mm +P loads can get pretty snappy).

A Bit Bored by it All

The P320X Compact comes in a lockable box, along with a pair of 15-round magazines and all the usual gear: manual, lock, paperwork.

Sig Sauer P320x 5
The rear plate on the slide can be removed and replaced with a red-dot optic.

I have to admit to being a bit blasé about testing the P320X Compact. I’ve shot enough P320s to expect that they will always go bang! each time; that they will eject the empties without fail; that the magazine will lock the slide open after the last round has been shot; and that the pistol will hit where I am aiming. In those regards, I have to say I was a bit bored—because they all happened.

But, while doing the chronograph work, I noticed that the impact area on the backstop was a rather small, dark spot. This led me to expect some good things from the accuracy testing, and there, I was also not disappointed.

Sig P320x table

Let’s not beat around the bush: The P320X Compact is aimed directly at the standard carry pistol in some quarters—the Glock G19. Same size, same capacity. However, the P320X Compact is better (except for its longer name).

The shell is rigid, so you don’t get the “squishy” feel of the Austrian 9mm. The chassis inside means the firing control parts are all supported by, and pivot off of, steel. This has a very marked and beneficial effect on trigger feel. Add in the straight trigger, with it perpendicular location when the striker is released, and you improve usable accuracy.

Sig P320x Specs

The standard night sights, with the replaceable plate for a red-dot optic, is pure 21st century. And then, the steel magazines that drop free when you press the magazine button? Just like old times.

Even with +P ammo, the P320X Compact doesn’t really have harsh recoil. You’ll know it is more than the standard 9mm or softy practice and competition ammo, but the shape of the frame distributes recoil evenly. You will have to shoot a veritable truckload of ammo to have your hands complaining as a result.

I’ve spent a long time shooting various .45 pistols, but the P320 in general, and the P320X Compact specifically, make the 9mm a lot more attractive than it has been in the past.

Raise Your Sig Sauer IQ:

The article originally appeared in the September 2019 issue of Gun Digest the Magazine.


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