In the world of handguns, the P320 is relatively new on the scene. It was introduced back in 2014 and rose rapidly in the ranks of service weapons. Then, in 2017, it was chosen by the United States Army to replace the M9 cementing its status as a top contender in the world of service and defensive handguns.

One of the reasons the P320 made a splash when it was introduced, and a definite element of its popularity, is the pistol’s modularity. The actual serialized part number - the gun as it’s defined by the ATF - is a drop-in trigger control group, allowing users to change out frames and slides for different sizes and purposes with ease.

For our build of the week this week, we’re showcasing a personal gun belonging to our Marketing Director. We wanted to capitalize on the P320’s modularity and show what high-quality parts can do for the pistol. The result is a compact gun that is absolutely incredible to shoot and filled with durable parts that will ensure this P320’s longevity.

We installed our P320 trigger control group into a Mirzon Enhanced Grip Module. The Mirzon has exceptional ergonomics; it’s designed around the shooter’s hand, and the subtle finger grooves work on a wide variety of hand sizes while the over-molded rubber grip panels provide a comfortable foundation to get a firm grip. The Mirzon also features a well-designed beaver-tail, allowing the shooter to get a high grip on the gun and minimizing felt-recoil.

Sig Sauer P320 group

The Grey Ghost Precision slide we chose to go with the Mirzon is exclusive to Rainier Arms, and in this compact format makes this P320 setup a viable carry option. The slide is available in a variety of colors, including black, and enhances the P320’s aesthetics. The grip serrations and improved coating make this slide a practical upgrade as well. It comes cut for a SIG ROMEO1, a Trijicon RMR, or a Leupold DeltaPoint Pro - any of these can be mounted on the slide straight out of the box without the use of bulky adapter plates. We’ve chosen a Trijicon RMR with an adjustable 3.25 MOA red dot, it’s a popular and reliable optic and the best news is that we have them on sale right now for just $375.

We’ve equipped the Mirzon Enhanced Grip Module with a PELT Trigger from Grayguns. The trigger pull is a full 2 pounds lighter than a factory-stock trigger, and 1.25 pounds lighter than even the X-Five variant. One thing to note about Grayguns triggers is that they are in use by professional shooters, which means they’re subject to on-going and rigorous durability tests and have to stand up to thousands and thousands of rounds of use and abuse.


Sig Sauer P320 Group 2

The fluted barrel we’ve included is from Faxon Firearms, it provides tight tolerances and an 11-degree target crown for superior accuracy. The color and profile make for a striking contrast to the Grey Ghost Precision slide, but this product is really about the finish. Both the interior and exterior are finished in a strong salt bath nitride, and the outside is coated in titanium nitride, making for a particularly durable and long-lasting barrel.

The modularity of the P320 makes it something like adult Lego pieces; it’s fun to create different builds and try new things. We have a lot of options for the P320 on the site, with more arriving all the time, but today’s build is all about shooting comfort and sheer durability. What good is a gun that feels good to shoot if you can’t shoot it for a long time?

Look out next week for our next build breakdown!