SIG Sauer recently announced a new caliber option for its hugely successful P320 platform of pistols – the 15+1 capacity 10mm XTen.

We've been evaluating this big thumper for the past several weeks and have all the details. 

Table of Contents

Shooting & Accuracy
Customer Reviews
Pros & Cons
Final Thoughts


The XTen was soft-launched earlier this year at the company's Freedom Days event in Arizona, where Phil Strader, SIG's director of firearms product management, told us that 10mm Auto was probably the most asked-for new caliber choice for the P320.

Using a completely redesigned grip module based on feedback from the popular XFive series, the new XTen sports an improved beavertail, an improved undercut at the trigger guard, and – this is key – a grip circumference almost the same as the XFive, something that is notoriously hard to get in a 10mm double-stack. 

The new SIG P320 XTen 10mm pistol
The new 10mm pistol runs a 5-inch barrel, similar to the P320-XFive Legion and P320 Max, both in 9mm. (All photos: Chris Eger/, unless noted)
The new SIG P320 XTen 10mm pistol
Weight, unloaded, is 33 ounces, which sounds chunky but is on the light side for a full-sized 10mm.

Plus, the XTen has a 15+1 flush-fit magazine capacity, which is super nice. This matches the vaunted Glock G20 and is in the same neighborhood as Springfield's newest full-sized 10mm XD-M offering and the new S&W M&P M2.0 10mm variant. 

The new SIG P320 XTen 10mm pistol
We found the loaded weight, with 16 rounds of SIG's excellent V-Crown JHP 10mm Auto 180-grain defense rounds, to be 41.9 ounces. 

SIG hasn't traditionally made a lot of 10mm pistols in the past – and those they did produce used older platforms – which makes the new P320-XTen special. For those curious, there was a SAO Elite variant of the P220 – coated in a custom Kryptek camo pattern – dubbed the Hunter that was available for a couple of years. Added to the SIG 10-milly list was the short-lived 1911 Tacops. Other than that, the P220 Legion has been offered in 10mm lately. 

The SIG Sauer P220 Elite Hunter
The SIG Sauer P220 Elite Hunter, a SAO 10mm coated in camo, was briefly made and still pops up in our Vault from time to time.


Specs (Via SIG) 

  • Overall Length: 8.5 inches
  • Barrel Length: 5 inches
  • Sight Radius: 6.8 inches
  • Height: 5.6 inches
  • Width: 1.3 inches 
  • Weight: 33 ounces (unloaded)
  • Magazine Capacity: 15+1 


Takedown is easy, with the well-known modular P320 fire control unit design, and can be accomplished without tools. This is an easy setup for future growth with the platform.

The new SIG P320 XTen 10mm pistol
Note the removable FCU – the pistol's serialized part – which means that future grip modules and variants could be on the schedule for the XTen series. Perhaps a smaller XCarry model? A tungsten-infused XTG competition gun? Let us hope. 
The new SIG P320 XTen 10mm pistol
Note the extended beavertail grip. This helps with control and recoil mitigation 
The new SIG P320 XTen 10mm pistol
When it comes to surface controls, the magazine catch is reversible, and the slide catch lever is fully ambidextrous. While the mag button is big and easy to actuate, the slide catch takes a little more effort and is tough to work without breaking a two-handed grip. For those who slingshot the slide, the catch doesn't matter as much. 
The new SIG P320 XTen 10mm pistol
The slide has both forward and rear serrations. Well-designed when it comes to use with heavy gloves, we found the XTen to have a nice, large trigger guard. 
The new SIG P320 XTen 10mm pistol
The new P320-XTen comes standard with SIG's excellent XRay 3 day/night sights and an optics cut.
The new SIG P320 XTen 10mm pistol
We mounted SIG's new ROMEO 2 micro-red dot on the XTen. It is a beast, especially in its enclosed and armored format, but the company says it is ready for the abuse of full-house 10mm rounds. All-up weight as shown, with 16 rounds of 180-grain 10mm loaded, came in at 46.2 ounces – which is still lighter than an optics-less 1911 10mm with half the capacity. 
The new SIG P320 XTen 10mm pistol with Romeo 2 MRD
Billed by SIG as designed and built "for the most rugged and adverse conditions" the Romeo 2 uses a 7075 aluminum housing that features a modular shroud system including two steel shrouds to provide multiple layers of protection and allows the user to configure their optic in three different profiles. A 1x30mm red dot that fits Sig's Romeo 1 Pro/DeltaPoint Pro footprint, the new Romeo 2 is available with either a circle dot or 3, 6, or 10-MOA red dot – with the circle dot and 10 MOA in the pipeline – and has 15 brightness settings. 
The new SIG P320 XTen 10mm pistol with romeo 2 MRD
The Romeo 2 comes with a lot of goodies as well as a multitool.

Besides its obvious use in competition and personal protection, SIG has been active in marketing the XTen as a personal carry choice for outdoorsmen in backcountry areas where large predators could be, and 15+1 rounds of 10mm Auto – especially if using heavy hard-cast bullets designed to penetrate deeply through thick skin and bone – can prove big medicine in such instances. 


Shooting & Accuracy

We headed to the range with a mix of 400 rounds of practice ammo consisting of Winchester white box, CCI Blazer Brass, and SIG's own Elite performance ammo, all in 180-grain FMJ ball. Added to this were about 150 rounds of self-defense ammo including SIG's V-Crown and Nosler's ASP, both 180-grain JHPs. We logged one malfunction – early in the evaluation with the WBB. 

The new SIG P320 XTen 10mm pistol on the range
The bulk of the ammo fired across our range trips with the XTen was in the form of SIG's Elite FMJ and V-Crown JHP. All of which ran flawlessly. 
The new SIG P320 XTen 10mm pistol
Typical accuracy with FMJ practice rounds fired off-hand from the 15. We had no problem working targets at ranges past 25, even hitting torso-sized steel at 50. 
The new SIG P320 XTen 10mm pistol
The only stoppage came from a spent Winchester FMJ case that failed to fully extract, jamming the slide open. We did not have the Romeo fitted at the time. It should be noted this was in the first two magazines of shooting. 
The new SIG P320 XTen 10mm pistol
The most consistently accurate round tested with the XTen was Nosler's ASP, which proved capable of cutting rings from the paper like a carnival shooting gallery. 

The flat-faced trigger is superb for a factory striker-fired pistol. We found it to break crisply at 4 pounds after just under a half-inch of travel at the tip of the bow, with a correspondingly short reset. 

The trigger in action: 

While a lot of 10mm pistols are a bit rowdy on the range, the XTen has excellent ergos that give it a controllable recoil impulse, and it is easy to get back on target even with personal protection rounds as seen below: 


Customer reviews of the XTen

Pros & Cons


  • Impressive 15+1 capacity
  • Optics ready with an RMR-pattern cut
  • Night sights are standard
  • Fantastic trigger
  • Decent price compared to similar offerings
  • FCU modularity
  • Dependable
  • Accurate
  • Controllable


  • Tough to carry concealed
  • Limited holster fits

Final Thoughts

The P320-XTen is a serious handgun that provides a great option for sportsmen in the field or even in home defense. It really feels and shoots like a big 9mm, something that a lot of 10s can't say. However, while lighter than a 1911 by a good bit, it is still every inch as long, wide, and tall, meaning that the XTen isn't really an option for those seeking a compact concealed carry piece – but that isn't what the gun was designed to accomplish. 

XTen compared to a Kimber Rapide in 10mm
Although much lighter, and with twice the capacity, the SIG XTen is about the size of a 1911, shown here next to a Kimber Rapide in 10mm.

Also, as the grip module and slide are different from a standard full-sized P320, holsters for the XTen are limited. Galco was quick to the market with a model of its High Ready chest holster while International has an OWB Kydex model.

When it comes to price, sure, you can get a G20 a little cheaper, but the G20 doesn’t come optics-ready with night sights installed or with a flat-faced trigger and great ergos. Seems like an obvious choice there. 

The new SIG P320 XTen 10mm pistol
Speaking of price, the new SIG P320-XTen comes in well under $1K. 


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revolver barrel loading graphic