The P365 family of handguns, Sig Sauer’s EDC powerhouse, is comprised of guns that run perfectly fine in their stock form. Sig has gone to great lengths to add modifications themselves to preempt the onslaught of aftermarket parts and mods. It hasn’t stopped the onslaught, though, and there are some excellent additions that can be made that will improve the way the guns carry and shoot.
A Brief Look Back At DIY Gun Mods
Twenty years ago, when I was first taking concealed carry seriously, there was one dominant type of EDC gun modification. Glock pistols, primarily the G19s, were often brutalized by amateurs with soldering irons. Some swapped out sights.
There was an entire subculture of 1911 mods and trigger jobs on revolvers. However, common handguns, the pistols that were built for duty or concealed carry, were usually left in their stock configurations.
Stippling, though, and Dremmeling finger channels became an absolute art form. Glock pistols were thinned, undercut, reprofiled, and textured in a myriad of ways that took something good to the next level.
Then came the extras. Magwells, mag release buttons, sights, threaded barrels, slide serrations or cuts, slide stops all the way down to the smallest springs: everything is fair game. On many guns, everything but the serialized component of the frame could be swapped out. And then, not to stir any controversy, the P80 craze kicked off.
What needs fixing on the P365?
I’m not even going to entertain that question. The gun runs exceptionally well in its stock configuration and comes in many variations. Now, with the Legion variants, there are even more options. Slides, barrels, and grip length—all available in some mix-and-match varieties.
But need and want are not the same. I carried a stock P365 for a while, and I had no complaints. Then I picked up an Icarus Precision grip, and it felt so different. That was a slippery slope. What had been a reasonably priced concealed carry tool suddenly became an increasingly pricey passion project.
Icarus Precision P365 frames
The Icarus has taken the concept of DIY frame mods and built them into aluminum. When Icarus began modifying the frame, they could add material as easily as they could take it away (which was the only choice for those Dremmeling plastic).
The control surfaces on the Icarus frame are exaggerated. A side-by-side captures the difference. This frame is an XL length: the Ace XL Evo. The back-strap is the best feature of the grip—it fills the hollow of the hand exceptionally well. And the ledges above the trigger guard are a solid addition, too.
The aluminum frames for the P365 have proven popular and now Sig has released their own version—the P365 AXG Legion. Its frame, though, still seems conservative when compared to the Icarus Precision builds.
Do you need a new slide?
There are so many variations now from Sig that I’d have a hard time making a convincing argument for a new slide. That said, others are working on new designs that make changes—mostly to the aesthetics. This one is a Lonewolf Dawn.
This is a build on Lonewolf’s Dawn 365 XL slide. It fits the Macro and XL-sized frames. The serrations are deep with distinct edges, but the remainder of the slide is understated.
These slides are stripped, so I’ve opted to keep the firing pin from the original P365 XL. Pulling that pin and getting it seated is hardly easy. Google. Youtube. Watch how it is done before attempting any serious manipulation of these tiny parts to avoid crushing accidents, bent parts, or launched springs.
All joking aside, disassembling the slide is easy enough but requires some patience and expert guidance. I can now say the same thing about the Fire Control Unit. It, too, has many small parts that have to be assembled in exactly the right order for them to all work functionally.
But we were talking about the slide, and when it comes to optics, the Lone Wolf P365 slides are milled for the Holosun 507K to mount directly without a plate—the same as the factory slides.
Do you need a new barrel?
Sig’s barrels are solid, but your factory barrel may lack functionality.
The only reason I’d choose to replace one is one of three reasons. One, I needed to (because of damage or something of the sort, which is highly unlikely). Two, if I wanted to run suppressed (more likely). Three, if I wanted to put on a compensator of some sort, that required the extra bit of barrel (most likely).
This one is a True Precision threaded barrel. This is a simple drop-in with a 1/10″ twist capped off by 1/2 x 28 threads. While this one is black, they come in a full rainbow of colors and finish options. I’m less inclined to go for garish colors, but if you want Gold, Copper, or Rainbow, True Precision has you covered.
What sights are best for the P365?
As I will likely include an optic on this build, eventually, and I often shoot suppressed, I’ve opted for a tall set of sights. The are XS Sights Minimalist Suppressor Height Night Sights. Serrated on the back to kill glare but still equipped with a bright front-sight dot, these are large and made of steel.
There are many options for aftermarket sights, and most do something similar. As most of us will be using red dots, the sights become more of a redundant system, but one that still needs to function properly.
Tall sights may pose problems for your holster, though—so choose wisely. The last thing you want is a tight fit that requires you to drag the front sight out with force.
Drop that Mag!
The Mag release button on this is an offset P365 Micro Extended Magazine Release. This odd design takes a minute to get accustomed to. It rides proud of the frame and sticks out. (Check out the image above on the Icarus frame.)
That’s the point, though. This protrusion is super easy to find, and the extra length provides extra leverage. While I thought, at first, that it would get in the way, it doesn’t. I’ve had it on the range a couple of times now, and I really like the way it works. The rest of my guns feel naked now.
Magazine well considerations
The Icarus frame has a really well-conceived magwell built in. If you are running a stock MACRO frame, though, I’d suggest the Tyrant Designs Flared Mag Well. It is exceptionally easy to install and adds a funnel to the bottom of the gun that speeds up reloads without getting in the way of concealed carry.
And the magazines themselves?
Some guns benefit from aftermarket magazines. Sig’s mags are typically rock-solid. The appeal of other brands is typically price or quantity. Sig doesn’t make a drum mag yet, but they’re available.
A magazine extension, though, is a solid add-on. If you’re gutting a P365 and really going to invest in making this the most effective gun for concealed carry, adding on a +3 from Tyrant is another easy way to make what’s already good even better. Not only will you add some control surface to the mag, but you also get three more rounds (and it even uses the factory spring).
You have options for magazines, from the new CA-restricted variety to the drums.
What’s left to do?
While I set out to build one ideal P365, I’ve now got enough spare parts for several. One will be a Frankenstein gun, and the other might be a more highly refined stock version. The trigger may be fair game. I’d like to shoot several to decide on the shoe-shape. And the levers could always be larger (like the slide stop). But that’s about all I’ll tackle and it covers what most can do before they begin milling truly custom creations.
Final thoughts
Some of these improvements are obvious. The frame takes what you might be inclined to do yourself and perfect it in metal—which is all but impossible for those of us who aren’t skilled with our home CNC machines.
Some are more subtle. The slide, in my opinion, improves the aesthetics. While this is an intangible, it remains significant. Every second you spend working with your gun builds familiarity. And that’s as important off the range as it is on. Making mods is how you create a carry gun that feels—tangibly and intangibly—like an extension of yourself.
