It’s an understatement to say that the Sig Sauer P320 pistol is a very popular handgun. It’s been around for (as of this writing) seven years now and continues to be a gun-owner favorite when it comes to modularity and reliability. In fact, it was the modularity that brought it to the top, winning the US military’s XM17 Modular Handgun System (MHS) contract in 2017, beating out the Glock 19X (not without controversy and angst), and replacing the long-lived Beretta M9. Now it’s the standard sidearm for all five military branches and many other law enforcement agencies—and that’s not even touching the civilian market.
“With its unmatched modularity, unprecedented accuracy, and its uncompromising reliability, the P320 is the official sidearm of all branches of the US military and has become one of the most sought-after firearms on the market.” ~Sig Sauer
The P320 series is based on the P250 frame and combines a striker-fired system with a modular chassis. Starting with the stainless steel Fire Control Unit (FCU), the rest of the pistol can be built to meet the user’s specific needs, from the slide to the grip module and caliber, including 9×19mm Parabellum, .357 SIG, .40 S&W, and .45 ACP.
Sig P320 Chambered in .45 ACP
Though each cartridge has its own purposes and advantages, here we’re focusing on Sig P320 45 ACP mags and grip adapters. Regardless of the decades-old 9mm vs .45 ACP debate, John Moses Browning’s cartridge isn’t likely to fade into the shadows of history. As Travis Pike puts it in his article, 1911s — Which is Best?
“The 45 ACP as a defensive round is often overshadowed by the capable and higher capacity 9mm round. The 45 ACP is a bigger projectile, and with modern defensive ammunition, it does offer the most expansive ammunition. Some 45 ACP ammo expands to nearly an inch as it travels through a soft target.”
The P320 Chambered in 45 ACP was introduced just a year after the 9mm P320 version was released
One thing that’s unique to the Sig P320 in 45 ACP is that it is not exchangeable with the other calibers. Unlike the 9mm, .357 SIG, and .40 S&W, Sig does not offer a Caliber X-change kit for the .45 ACP. So, you can’t change your .45 to one of the others, and vice-versa: if your P320 is not .45 ACP, you can’t change it to .45 ACP. Reportedly, Sig Sauer planned to release an exchange kit for this purpose, but it’s been a few years since they said that and they’re still not available. Though this does restrict a bit of the modularity in terms of caliber, there is still plenty of leeway in frame size depending on which grip module you use. A full-size Sig P320 .45 ACP converted to compact has a longer slide and barrel with a shorter grip and dust cover, though the width remains the same.
Restock Your Mags!
If you need mags for your P320 in 45 ACP, we’ve got two magazine options available at GunMag Warehouse—a 9-round compact and a 10-round full-sized. These mags are the same factory mags that came with your gun, made in Italy, and they’re also compatible with the Sig P250.
We’ve also got grip adapters to enhance the safety and comfort of these magazines.
Ideal for target practice and tactical drills, this 10-Round magazine is still built to Sig Sauer’s exacting standards from high-quality carbon steel.
Take a closer look at the magazine in this video:
Why would you need a grip adapter? Well, aside from enhancing the ergonomics of your grip, these adapters also prevent magazine over-insertion, thus protecting the internals of your pistol. The snap-fit installation is quick and easy and doesn’t require any tools.
X-Grip magazine adapters are considered the industry standard, trusted by top military and law enforcement professionals. Made of a high-quality, impact-resistant polymer, they’re perfect for range trips, training days, and for use on backup mags in concealed carry.
Stephanie Kimmell is the firstborn daughter of Missouri's Pecan King, worthy scion of a Vietnam veteran sailor turned mad engineer-orchardist-inventor-genius. With a BA in technical writing, she freelances as a writer and editor. A Zymurgist greatly interested in the decoction of fermented barley and hops, she is in many ways a modern amalgam of Esther Hobart Morris, Rebecca Boone, and Nellie Bly. She hunts, fishes, butchers, and cooks most anything. When not editing or writing, she makes soaps and salves, spins wool, and occasionally makes cheese from cows she milked herself. Kimmell is a driven epistemophilic who loves live music and all sorts of beer.