Sig Sauer P365 Upgrade Part 2

Sig Sauer P365 Upgrade Part 2

Sig fine-tunes the smallest blowback action pistol

By Dennis Adler

It is not unusual for gunmakers to go back and improve a design, it is, however, unusual for an airgun manufacturer to do this, and in most cases it’s a long time in the making. For centerfire (and rimfire) guns, safety concerns over a design flaw, or a discovered weakness in a part is often a driving force for change, other times, it is to improve accuracy or durability, or to respond to consumer demands. There are examples of all these circumstances with handguns and rifles, but you would have to look much harder to find an airgun manufacturer that has implemented changes to a new design less than a year after its introduction for no other reason than to improve performance and reliability. But that is exactly what Sig Sauer’s Sig Air Division has done with the P365.

Sig Air Division engineers went back into the magazine and firing system design and made improvements to the porting and balance of the valve. This reduced cooling of the gun and was also part of the increase in the blowback action, giving the air pistol an even more realistic feeling when fired. Combined with a better trigger that runs smoother and requires less take up to break the shot, you end up with the 2020 model of the P365. Same gun, works better.

The 2020 model is an improved air pistol. This does not imply that the 2019 guns were not good, in fact, they were more than impressive as a groundbreaking design, but issues arose with consistency of performance due to the gun’s remarkably small size, and with the smoothness of the trigger pull. The latter is an issue with more than a few CO2 air pistols on the market, but it is seldom addressed by manufacturers; it is just a given that it is simply the best trigger that can be made for that CO2 pistol. This applies more so with lower priced models (well under $100). This is less common with guns that fall into the $100 to $150 price range, but it still happens. We accept it as the best it can be. Sig Air did not accept that in its own design for the P365, just as Sig Sauer would not accept it with a centerfire model. Thus improvements to the smallest self-contained 12 gram CO2 BB magazine on the market and the P365’s firing system, slide, and trigger were implemented as soon as possible, and the testing standards for the CO2 pistol made equal to the P365’s centerfire counterpart. This would make a world of sense if the P365 were retailing for $149.95 but it only retails for $99.99 and sells for less than $80. And spare magazines sell for less than $20. Why do it? It is safe to say that Sig Air responds to problems or consumer concerns as quickly as possible. But what does this mean for the 2020 P365 models?

Measurements don’t lie; the P365 is shorter than either the Walther PPK/S or PPS CO2 models, which are closely scaled to their centerfire counterparts but larger than the P365. As a centerfire model, the two Walther models chamber .380 ACP while the smaller Sig P365 chambers 9mm. As CO2 models, the P365 is equally impressive because it uses a self-contained CO2 BB magazine while the larger Walther PPK/S and PPS have separate CO2 chambers in the grip and use stick magazines. Only the PPS has higher velocity, the PPK/S and Sig models cannot break 300 fps.

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First off, there is no change in velocity, the Micro Compact blowback action CO2 pistol still has an average velocity under 300 fps. With Umarex Precision steel BBs, velocity was 293 fps to 297 fps, with Hornady Black Diamond, 287 fps to 299 fps (on fresh CO2). I know that is still below the benchmark for most air pistol enthusiasts and compares, unfortunately, with the long in the tooth Umarex Walther PPK/S, which also cannot clear the 300 fps hurdle. The difference is that the PPK/S also suffers from a lack of accuracy at 21 feet, delivers only modest felt recoil, and has non-functional features. It is also priced considerably lower than the Sig, and is considered an entry-level BB gun with separate CO2 and a stick magazine. Still, better performance than the old PPK/S was expected from the Sig Sauer P365. But it is only on the velocity end of things where it seems to fall short, while it vastly exceeds the Walther in accuracy, range, handling, and authenticity to its centerfire counterpart. I guess that’s something.

The trigger improvements found on the 2020 version added to other changes is the combination that makes the new model a better gun to shoot. The feel of the triggers is like night and day, even if they look the same.

Trigger pull

This is an interesting area for Sig Sauer to have focused its fine tuning attention since the original trigger was not that bad, just a little heavy. The new tuned action is a lot better, and that means the gun will be easier to shoot consistently. Here’s the surprise, trigger pull on the 2019 model averaged 5 pounds, 6 ounces. The 2020 model averages 6 pounds, 13 ounces and requires 0.375 inches of total pull to break the shot. It is heavier and longer, but has no drag or stacking, it is as smooth as a centerfire pistol with 0.312 inches of effortless take up and a mere 0.0625 inches to break the shot, versus a heavy 0.125 inches with the earlier trigger.

Can the same gun with a few minor tweaks become a superior gun over its predecessor of the same design? It absolutely can and the proof is in the handling and accuracy.

When you fire the 2020 P365 the slide slams back like a .22 and the report is even louder than the 2019 model. With the latest P365, the benefits aside from improved reliability, is overall feedback. The P365 feels closer to an actual handgun with the improved trigger pull and felt recoil. As a 1:1 training gun (less field stripping capability) the P365 is a perfect understudy to its 9mm counterpart. Of course, so was the 2019 model, this one just feels better. New buyers will be impressed. Owners of the earlier gun, going for a second chance, will be even more impressed.

While doing the chronograph test for the 2020 model I shot Umarex Precision steel BBs and Hornady Black Diamond black anodized steel BBs. This is 17 out of 20 shots through the chronograph from 21 feet. The remaining three hits were just outside the bottom edge of the small 2-inch circumference Shoot-N-C bullseye target. Multiple overlapping hits knocked out a piece of the bullseye. The sights are almost dead on POA at 21 feet.

Just as a preview of what the P365 is capable of at 21 feet, I used a 2-inch Shoot-N-C bullseye on the backer board for the velocity tests. All but three rounds were inside the 9 and 10 rings of this little bullseye target for a spread of 1.77 inches with 8 inside the 10 at 0.875 inches.

In Part 3, more downrange accuracy at 21 feet and beyond.

3 thoughts on “Sig Sauer P365 Upgrade Part 2”

  1. How are we supposed to tell if we are being sold a 2020 gun?
    I have my suspicions here . My Sig 365 has never been very reliable. It is the second one the first having been replaced under warranty. Currently I have one mag unusable due to leaks.It is always a matter of surprise when it works properly down to the 12th round and locks back. Often you are cascading bbs out of the barrel. On one or two occasions the slide has given a good impression of automatic fire rocking backwards and forwards but without collecting a ball.
    It is very suspicious that they should modify it so quickly. I wonder if there have been a large number of returns necessitating these modifications.

    • Derek:

      According to Sig Sauer’s Sig Air Division, production on the first series of P365 CO2 pistols ended last summer and guns in the pipeline were all sold before the end of the year. As late as December 2019, the newer guns were already being delivered to retailers. I got mine on December 20th along with two spare magazines. The likelihood of purchasing a 2019 gun today is nil from a retailer like Pyramyd Air. The one very immediate way to know if you have purchased a 2020 gun is the trigger, it feels nothing like the trigger on 2019 models, as I pointed out in Part 2 of this review. As for your older model, I would try one of the 2020 magazines in it. Valving and over cooling were the problems which have been corrected. I don’t know how many were returned for the problem you describe, safe to say enough to hasten an immediate update to the guns. As far as I can tell from my 2020 test gun, the issues you and others experienced (myself included later on after my initial reviews), have been addressed. If you liked the P365 when it came out (troubles not withstanding), you will like the 2020 model more. It is a better air pistol and even closer in feel to the 9mm model.


      • I wonder therefore whether Sig should be offering to replace our old models with the new one or at least giving us a hefty reduction on the price of a new one ? How much gas have wasted!!

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