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Sig P320 vs. P365

Sig P320 vs. P365

Mar 9th 2023

The Sig Sauer P320 and P365 series of pistols are two of the fastest, up-and-coming pistols in the United States. Both are from a very reputable manufacturer. Both have overcome some initial challenges and established reputations as reliable. Both are highly modular and lend themselves easily to different frames and slides. Ultimately, though, these are two very different pistols. Let’s take a closer look at the differences in these two Sig P-series strikers-fired pistols.

Sig P365

The Sig P365 was introduced to the public in 2018. It was an absolute game-changer, though. It was smaller than many of the ultra-compact, single stack 9mms. Unlike the competition, it held ten rounds in its short, flush fit magazine rather than 6 or 7. Since it was introduced every manufacturer has copied it. The Shield Plus, Springfield Hellcat, and Ruger Max are all based on the P365. But the P365 is the original double-stack, micro-compact pistol. In fact, with its tiny size and 10-round magazine, it is probably the first pistol ever called a “Micro Nine.”

The P365 is chambered in 9mm Luger. A newer version is offered in .380 ACP. The initial appeal of the P365 was its small size coupled with a duty caliber. It is incredibly small for its capability. Anyone can make a small gun, but Sig made one that held a lot of rounds. They also made one that wasn’t punishing to shoot. The P365 is snappy, but very soft shooting compared to other guns in its class. On top of its tiny size, 10-round magazine, and controllable recoil, the P365 also has a fantastic trigger pull. It is short, crisp, light, and has a great reset, and easily bests a stock Glock trigger. Concealed carriers immediately sensed the value in the P365, and it was an instant hit.

Almost immediately, Sig began introducing variations of the P365. These include the P365 XL, a long-slide version with a slightly longer grip. The XL model holds 12+1 rounds, and its magazines are backward-compatible to the smaller 365s. Not only does it take a 12-round magazine, but it also offered a full grip and a flat trigger. Now Sig is making a P365 X Macro, a not-quite-full-sized version of the P365, with an even longer grip, holding 17+1. Again, the 17-round Macro mags work on smaller P365 frames.

The Sig P365 is based around a Fire Control Unit (FCU). This is essentially the trigger assembly and slide rails. As the serialized component of the gun, the FCU is the only part legally considered a “firearm.” As a result, all other parts of the gun can be changed out at will, including the grip frame, slide, and barrels. This has led to all sorts of variations, including the P365X, which is a standard P365 slide on an XL grip module. End users can purchase shorter or longer slides, grip modules, and barrels to mix-and-match as they please. This has also led to a booming aftermarket of grip modules and other parts for the P365.

Sig P320

The Sig P320 was introduced a few years before the P365, in 2014. Though it had some fans, it didn’t gain widespread appeal until it was adopted by the U.S. Military. Dubbed the M17 and M18, the P320 won the military’s Modular Handgun System trials in 2017. The P320 is a series of polymer-framed pistols with ambidextrous controls including the slide lock. The P320 comes in traditional full-size and compact size.

Magazine capacities in the full-size versions are on par with other, modern pistols: 17-rounds in 9mm, 14 rounds in .357 Sig and .40 S&W, and 10 rounds of .45 ACP. Compact magazines that fit flush with compact frames are available, with slightly smaller capacity. A larger capacity, 21-round 9mm magazine is available. It is adaptable to work on both large and compact frames.

Like the P365, the P320 is completely modular. Centered around a Fire Control Unit, the P320’s grip modules, slides, and barrels are interchangeable. This lets the user manipulate one gun to be larger or smaller as needs dictate. Unlike the P365, the P320 is also available in a wide variety of calibers. The P320 can chamber 9mm Luger, .357 Sig, .40 S&W, 10mm Auto, and .45 ACP with nothing more than a change of barrel and magazine. It is one of the most modular handguns on the market today.

Sig P320 vs P365: Differences

These pistols obviously share a great deal of similarities. Obviously, they share some pretty significant differences, too. Let’s take a closer look at those.

Size: The size of these two guns is different. The P320 is a true double-stack pistols. Its size is on par with other standard semi-autos like the Glock 17/19 or S&W M&P/M&P Compact. The P320 is noticeably larger, even with the compact frame and slide installed. The compact P320 grip still offers a full grip. The P365 is a marvel of compactness in its smallest variation. And it can be scaled up to an almost-duty-sized version. Both are very versatile, size-wise, but the P365 is, hands-down, the smaller of the two. The small grip circumference might be a boon to shooters with smaller hands, and a bane to those with larger mitts. This is a personal preference factor that you’ll have to apply to your own situation.

The P365 has a 3.1 inch barrel, and the P365 XL has a 3.7 inch barrel. The P320 has substantially longer barrels. The P320 Compact has a barrel length of 3.9 inches, longer than even the XL barrel. The full-sized models have a barrel that is 4.7 inches long, a full inch longer than the P365 XL. This produces additional velocity as well as providing greater sight radius.

Weight: As a result of being smaller and carrying less ammo, the P365 weighs much less than the P320. The P320 Compact weighs in at about 28 ounces. The standard P365 weights only 18 ounces. That’s over half a pound of additional weight on the larger P320. If comfortable concealed carry is your goal the P365 might be the better bet. If home defense is your goal the weight might be advantageous and the P320 might be the best option.

Caliber: The P365 is available in 9mm, and .380 ACP was recently added. This is likely not a limiting factor for most people. Nine-millimeter is the top-dog defensive chambering, and the cheapest centerfire ammo going. Very few people are going to have an issue with this. The P320, on the other hand, is available in 9mm, .357 Sig, .40 S&W, 10mm Auto, and .45 ACP. If you or your agency desires one of these larger calibers, the P320 is the option to go with.

Accessories: Both the P320 and the P365 are very versatile when it comes to mounting accessories. Both have options available for mounting a red-dot optic. Red dot optics can improve both speed up close and accuracy at a long distance. Weapon-mounted lights are critical to success in low-light conditions. Both also have a provision for mounting lights and lasers, but they are different. The P320 has a Mil-Std-1913 rail on the dustcover. This is a universal mounting system and will take almost any WML on the market. The P365 has a proprietary rail. There are only a few lights that will fit it, like the Streamlight TLR-7Sub and the Surefire XSC. This does somewhat limit the P365 vs. the P320.

There are a number of other accessories available for both of these pistols. With the modular nature of these guns, they really are "do it all" pistols. Holster fits for both of these pistols are also widely available, due to their tremendous popularity.

Shooting: both of these guns offer a phenomenal shooting experience. Both are accurate and reliable. The P320 has less recoil, though. It offers a larger grip surface, and longer barrel. It also offers substantially more weight, helping to absorb recoil. This is especially true when a full-size WML is added to the P320; a few more ounces up front help tame recoil even further. The P365 is surprisingly soft shooting for its size. It is a very small, very lightweight gun, and the recoil is certainly noticed in 9mm. The .380 version doesn’t suffer this ill, and maybe a good option for recoil-sensitive shooters. Both guns are very ergonomic with excellent grip texture, and both have front slide serrations.

Safety: Both of these pistols are offered in versions with and without a manual safety.

P320 vs. P365: Which is Right for You?

Both the Sig Sauer P320 and the P365 are phenomenally good pistols, and there is no clear winner. Both are exceptionally good candidates for personal protection. The P365 is slightly better suited to concealed carry, but at the expense of having lower capacity, being slightly harder to shoot well, and having a proprietary rail. The P320 is larger, which makes it more difficult to carry. However, it is easier to shoot, having a larger grip surface, and more recoil-absorbing weight. It also has a higher magazine capacity and is versatile with more accessories.

The choice really comes down to user preference and needs. Do you need a gun for day-in, day-out concealed carry? Some variation of the smaller, thinner, lighter P365 is probably going to be your best bet. Are you looking for a gun for home defense and target shooting with a full grip and less recoil? We’d probably steer you toward the P320. Are you looking for something that does both? Either one of these guns would be great options, as long as you understand their strengths and weaknesses.

Sig P365 & Sig P320 Night Sights

Regardless of which you choose, the P320 or the P365, XS sights has your sighting solution. We offer a full range of sights. Our F8 Night Sights, features front sight with a huge orange dot. A tritium vial is in the center of the front sight dot, and the rear sight has a single tritium vial. During daylight just find that big, orange ball; in low-light conditions simply align the glowing dots vertically. These offer fast, precise sight alignment in the worst-case scenario. We also offer night sights with a more traditional, three-dot arrangement. And of course, our famous “Big Dot” sights are as popular as ever.

Important note on P365 sights: beginning last year, Sig began producing P365 XL slides with dovetails for standard rear sights, even on versions with an optic mount. Models of the P365 X and XL manufactured prior to this had a weird rear sight held on by screws. This created some manufacturing problems, and these sights were scarce as hen’s teeth on the secondary market. The updated models have a simple dovetail. This allows the P365 X and XL to utilize sights common to the entire P-Series line.