SIG Sauer P320-XTen 10mm Pistol: Full Review

After months of whispering, SIG Sauer unveiled the new P320-XTen, moving the P320 up a full centimeter. With the introduction of the P320 series in 2014, SIG Sauer took the idea of a modular, chassis-­based pistol system mainstream. The P320 series evolved quickly, even while the U.S. military adopted early configurations of the P320 as the M17 and M18.

Announced on May 26, 2022, the P320 design is now chambered in the powerful 10mm. Called “XTen,” it is a full-­sized, variant of the P320 X-frame built around the stainless-steel P320 fire-control unit (FCU). The P320-XTen ($799) model introduces a new, large-size frame and slide. Fans of big-­bore, full-sized pistols should consider this new entry, which competes against the Springfield Armory XDm Elite OSP ($653), Glock 20 ($649), and Smith & Wesson M&P10 ($665), to name a few. 

At 81/2 inches long, the XTen is a half-inch longer than the closest comparable P320 9mm variant. Its 33-­ounce heft is 3 ounces heavier, too, and the width remains the same. The longer 10mm cartridge did necessitate a slightly larger frame in the grip area. Looking at the stats on paper is deceiving.

That extra size of the P320-XTen is mitigated by the thoughtful design of the improved X-­series grip module. The deep undercut at the back of the triggerguard and the beavertail allow the user’s hands to get high on the pistol. The polymer frame also features a newly engineered grip texture for the heavier recoiling 10mm cartridge. The rough texture is reminiscent of shark skin and is embossed into the frame in panels on the sides of the grip, the frontstrap and the backstrap. 

The magazine release is reversible and the dustcover features a five-­slot Picatinny-spec rail. The slide lock/release levers are ambidextrous, small and well placed for access on either side by most hands. The triggerguard is large and suitable for gloved hands. The trigger is SIG Sauer’s successful X-­series flat-faced unit. As of this writing, black is the only available frame color. 

The black Nitron-finished slide is stainless steel. It features the typical SIG Sauer grasping grooves at the front and rear. The coating was even, smooth and effective. Guns & Ammo’s editorial staff shot the pistol in an unusual summer storm and put it away wet. We retrieved it a week later to finish testing and found no evidence of rust. The slide is topped with the brand’s X-­RAY3 day/night sights. It is optic compatible for a wide variety of dot sights, too. The slide houses a 5-­inch, carbon-steel, Nitron-coated bull barrel.

For testing, the new SIG Sauer Romeo2 red-dot sight was mounted to the slide to extract the pistol’s accuracy potential. The Romeo2 is SIG Sauer’s newest pistol-­focused electro-­optic. It features a 3 MOA red dot, rubberized buttons on the left side to adjust the intensity through 15 levels — 12 visible and three night vision, a side-loading tray for the CR2032 battery and click-adjustable slot head screws for windage and elevation. The Romeo2 is unique in that it can be user modified from an exposed-emitter optic to a closed emitter. It’s a clever system that features two additional component parts, a rear window and an outer shell that attaches to the optic body. To change it, the shooter simply places the rear window in a ledge to the rear of the optic body. The window is wedge shaped in profile, which allows it to rest against the rear edge of the optic window. The rear window is polycarbonate and has a gasket around the areas where it contacts the optic body. The shooter then hooks the crossbar of the steel outer shell in a notch at the front of the optic body and rotates it down into place, like a hinge. The outer shell traps the window, allowing the gasket to make a seal. The user then fixes it into place on each side using the provided T6 fasteners. It’s easy to convert and a very secure system. G&A tested it with several 3-­meter drops over concrete and rocks. Some also used the optic body to rack the slide off a wooden barricade. It was scratched and dinged, but it never failed. Battery life is advertised at 25,000 hours, helped by the unit’s motion-activated sensor.

With the Romeo2 mounted, the XTen proved itself even better on the range through multiple sessions. We put some 600 rounds of mixed ball and hollowpoint ammunition through it for its initial testing. At approximately round 60 there was a failure for a round to go into battery, but it was a malfunction that never repeated itself. No other malfunctions were noted. 

The XTen ships with two 15-­round magazines, and while the first 14 rounds were easy to load, the last one was tough. The combination of the beveled magazine well and the steel, double-stack magazines did make for easy reloading, and the expended magazines ejected easily.

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Shooting the XTen is unique. The shooters used to bigger calibers found the ergonomics of the pistol helped mitigate the felt recoil. For an experienced shooter, the XTen is among the easier of the 10mm pistols on the market. The X-­series grip and texture were positive contributors. The heft and balance of the big pistol also made it easier to transition between targets. If you are an inexperienced shooter used to 9mm recoil, there will be an adjustment period.

The combination of the 5-­inch barrel, the Romeo2 optic, and the 4-­pound, 4-­ounce-measured flat-face trigger supported the XTen in producing some impressive accuracy. Most groups were smaller than 2 inches. SIG Sauer’s 180-grain V-­Crown was the most accurate load tested — with a 1.6-­inch average! G&A has reported on 10mm M1911A1s costing more than $2,000 that did not shoot as well.

While the case for needing a 10mm for carry might not be common, the case for wanting a 10mm is. With a $799 retail price, the P320-XTen represents a potent combination of performance and value. Imagine if we had this pistol available when the 10mm was introduced in the 1980s! 

SIG Sauer P320-XTen

• Type: Striker fired, recoil operated, semiautomatic
• Cartridge: 10mm
• Capacity: 15+1 ­rds.
• Barrel: 5 in.
• Overall Length: 8.5 in.
• Weight: 2 lb., 1 oz.
• Sights: SIG Sauer X-Ray3 Day/Night; optic ready
• Finish: Nitride (steel)
• Trigger: 4 lbs., 4 oz. (tested), flat
• MSRP: $799
• Manufactuerer: SIG Sauer, 603-610-3000, sigsauer.com