The Sig Sauer P320 X5 Legion has been on the market for a little while now. So I wanted to bring you a review after shooting more than 30,000 rounds through mine over a year of competing in 3-gun and USPSA. I chose this platform for its ergonomics, weight, and magazine capacity. With its competition-based design and upgrades from Grayguns, this pistol is pretty sweet. 

Why the X5 Legion Is Great for Competition

Right out of the box, the X5 Legion can be a workhorse. It comes with many features that aid the competitive shooter but would be equally helpful for those looking to pick up an X5 for home defense as well. With a five-inch barrel, the gun is plenty accurate for both. Let’s check out how this gun is ready to rock out of the box. 

Let’s first talk about the tungsten-infused grip module. Infusing the grip module with tungsten brings the X5 Legion to 43.5 ounces. That is heavy for a striker-fired pistol. But the weight helps tremendously with recoil reduction and transitions. This gives it the weight of a metal gun – such as a 1911 – with the ergonomics of a striker-fired pistol. The tungsten grip is a great reason to get the X5 Legion. 

Next up, the flared magwell is huge in helping with reloads. The magwell creates a funnel that simply sucks in magazines. Sig also added an extended slide release for this gun, which makes it that much easier to drop the slide. 

The flared magwell sucks in mags. (Photo: Taylor Thorne/

Another big bonus is capacity. The X5 comes with either 17- or 21-round magazines. If you opt for the 21-round magazines, there are extended baseplates to bring the total round count to 23. This may not sound like a huge benefit, but that is the difference between having to reload one target less in a competition. The 21-round magazines also make reloading with the flared magwell easier because the 17 rounder will sit completely flush. 

One of the final big upgrades for the X5 Legion is the slide. It allows you to directly mount one of the most popular optics: the Sig Sauer Romeo 1 Pro. Direct mounting is a benefit because it negates the risks that come with mounting plates such as cracking or coming loose. You can also check out our article on the best optics of 2020, where I reviewed four optics with the X5 Legion. 

Related: Top Optics to Trick Your Guns Out in 2020


The modular frame of the P320 platform allows you to completely remove the fire-control unit. There are a few benefits to this. The fire-control unit is the serialized part of the gun. In most striker-fired pistols, the grip is serialized. This means you have to buy a new gun if you damage or break your grip. 

There are a lot of benefits to having the fire-control unit be serialized and removable. (Photo: Taylor Thorne/

You can now take the fire-control unit and place it into another grip. Sig offers many grip options for the P320, some people also like to have ones with varying textures or designs. Also, if the gun gets dirty, it can easily be disassembled and hosed down. I’ve had to do this a few times during competition where things got rather crunchy from dirt. 


Another great benefit of the Sig Sauer P320 lineup is there are lots of aftermarket parts and shops that can work on your gun. Grayguns overhauled my X5 Legion, not that it needed it. But as competitive shooters, we are all about the upgrades to make shooting that much easier. I trusted Grayguns because Bruce Gray actually collaborated with Sig Sauer to design the P320 platform. Needless to say, they know it best. Grayguns is also the top Sig custom shop in the country. Let’s take a look at what they did:

Grip Reduction: Out of the box, the P320 features a blocky grip. I thought there was room for improvement. The grip reduction narrowed the circumference as much as possible, shaving down the shelf and deepening the groove under the trigger guard. This is the most noticeable modification I’ve ever made to a pistol. It allows the hands to gain more purchase and brings the grip up higher. This improves both recoil management and comfort. Yes, my hands are small. But after letting others try this grip, they wanted to sign up for the upgrade. It simply feels better. 

Silicon Carbide: Applying silicon carbide takes away the slippery feel from the grip. In short, silicon carbide is ground up and applied with epoxy. After a bit of shooting, most people will feel their sweaty palms slipping off the grip, which is not an ideal situation. There are many alternatives for applying grip texture, from grip tape to stippling. Grip tape wears easily. I replace mine at least two times a season. Stippling is great, but it is not as aggressive as silicon carbide. 

The silicon carbide grip is not only functional but looks great as well. (Photo: Taylor Thorne/

Competition Hybrid Trigger: A Sig from the factory has a roughly 6-pound pull. With the Grayguns trigger, I’m now pulling back a mere 3.5 pounds. There is a noticeable weight difference and the crispness of the break also improved. This upgrade has helped with accuracy and quick follow-up shots. Flat triggers have become very popular, but I personally like the curved trigger because it brings the trigger closer to my finger. I have small hands, so the trigger being closer makes a big difference in trigger control and allows me to fully reach the trigger. 

The curved trigger has an advantage for people with smaller hands. (Photo: Taylor Thorne/



Shooting the X5 Legion, especially tricked out by Grayguns, is simply awesome! The weight of this pistol reduces muzzle flip and recoil, which helps with follow-up shots and target transitions. The grip angle is also very natural and allows for a natural sight picture. It’s a great shooter. But as a competitive shooter, I need it to function every time. I need to know that it is reliable.

It shoots as good as it looks. (Photo: Taylor Thorne/

Enduring over 30,000 rounds in a year, this gun has held up great. The only issues I’ve had were a failing extractor and a broken slide release. With high round counts and competition abuse, these are very minor and somewhat expected issues. Even under dirty circumstances, this pistol just keeps on running. 

It also cycles any kind of ammo, from hot 115-grain box ammo to light 147-grain reloads. The X5 does come with a second set of recoil springs. These are included so you can shoot lighter ammo. As a side note, my springs and followers are in great condition after high usage.


After tens of thousands of rounds, I can confidently conclude the P320 X5 Legion is a solid choice no matter what your use case. This is an ideal competition pistol, but it can become elite with just a few upgrades. 

revolver barrel loading graphic