Over the years, my EDC pistol has varied quite a bit. Finding a pistol that is easily concealed on a small frame has historically required compromising on a compact gun with reduced capacity and shootability.
Several years ago, a single-stack G43 was the only gun on the market that I could carry with complete concealment. I built an awesome G43 with an aftermarket compensator that was very shootable, but the capacity of only six rounds in a flush magazine was far from what I considered ideal. Then Sig Sauer came along with the P365 and revolutionized the micro-compact market. By the time the P365XL hit the market and the initial kinks of the platform had been solved, I was ready to make the switch. I torture-tested a stock P365XL with thousands of rounds until I was satisfied the platform was truly reliable. At that point, I was ready to embark on a journey to build one just how I wanted.
This immediately brought to light one of the truly genius design aspects of the P365; the modular design is centered around the Fire Control Unit (FCU). In essence, with the introduction of the FCU, Sig created an easy-to-build platform like an AR which has been embraced by the firearms community. Many companies are now building all kinds of components and unique accessories to make the P365 infinitely customizable. The great thing about the design is only the FCU is serialized so you’re free to select every other part or send it off for customization without the cost of FFL transfers including the grip module. Getting a grip stippled on other firearms means the cost and headaches of transfers.
My first P365 build was customized by Danger Close Armament, with some small modifications I made along the way. Initially, this was simple: I changed barrels to have a compensator, added a rail adapter from Tactical Development so I could use a better light, installed a Shield RMSw, and a new trigger shoe from Armory Craft. These were all small easy mods that made the gun my own, but there was one key thing missing that I wanted for my EDC: actual backup rear iron sights. Personally, I always find the smaller window red dots lacking since you have to hunt for the dot when you come up on target. When real irons are present, my eye sees the rear iron when bringing the gun up and it naturally guides the dot into picture without effort. Even though I had a good functioning EDC, I was already planning a new build, this one without any compromise.
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Starting My New Build
Over the last couple of years, I have followed the burgeoning group of manufacturers developing new products for the P365 and slowly chose all my parts for my new build with great care. My overall goal for this build was to have the flattest shooting, most reliable, and most good-looking EDC I could put together.
For the first several P365s that I modified, I had to buy an entire gun making it more expensive and I have a pile of spare parts lying around not being used. Thankfully, just like they did with the P320, Sig has released the P365 FCU from their custom shop. This is a big plus since you don’t need to buy a whole gun just to build what you want anymore. Plus, the trigger in the FCU from the custom shop has a cleaner break and crisper reset than the stock triggers. In previous builds, I ended up replacing the trigger shoe and polishing internals, but with the custom shop FCU, no modifications were necessary. Additionally, the Titanium Nitride finish looks really good with the color theme I chose for my newest build.
Selecting The Ultimate Grip
Lakeside Gripworks is a company that specializes in awesome stippling packages for the P320 and P365. After previously getting one of his grip modules, I knew I wanted one for this build. I prefer a nice contoured grip with an aggressive texture. Lakeside’s Drago texture is exactly what I was looking for. It has a great aggressive grip for all conditions that looks awesome and feels great in the hand. I always wear an undershirt so the aggressive texture is no bother for concealment, but if you prefer something less aggressive against the skin, his EDC texture is also a great option while still having a solid grip. He works with several awesome cerakoters to finish grip modules before stippling and I chose mine in an attractive gold multicam.
To go with the grip I selected an extended mag release from Armory Craft. It has a slightly larger profile making it easier to depress without any movement of my grip as well as a nice checkered surface that you can still use when wet. In damp conditions, the stock mag release will slide against my thumb making it less ideal for less optimal conditions.
Giving It The Gas
One thing I wished about the P365 from the beginning was that it would have a standard rail so you can use any light or laser accessory instead of the proprietary one Sig designed. Tactical Development is a company that has been constantly innovating accessories for the P365 with rapid development cycles thanks to 3D printers. I’ve been using his P365 rail adapters for several years now and his most recent iteration is my favorite yet since it combines a go-fast pedal and the standard Picatinny rail adapter. Just like go-fast pedals on competition pistols, this one gives you additional leverage with your support thumb helping to keep the gun flatter with recoil, and also gives you a consistent position to place your thumb rapidly. You might think this adds too much bulk to an EDC, but it adds about ¼ of an inch at the front of the pistol where it easily disappears in a good holster where a lot of holster companies add thickness like a wedge to help keep the grip tucked close to the body.
Let There Be Light
Thanks to the rail adapter from Tactical Development, I was free to add any light accessory to my pistol. Instead of a 100-lumen Streamlight TLR-6 for Sig’s proprietary rail which I find sadly lacking, I chose the Streamlight TLR-8G. It gives five times the light while still being compact enough to carry discreetly. As for the laser, I generally don’t use them, but for low-light conditions, I like having the extra option. In some low-light conditions it can be challenging to use tritium night sights or red dots quickly so having the option there is an extra edge if necessary.
Choosing the Perfect Slide Components
Initially, I planned on using a P365XL slide that allowed me to keep the rear irons with a red dot. These have recently become available, but in following the community customizing P365s, I found a much better option. Parker Mountain Machine makes a barrel and compensator that when installed with a standard P365 slide, has the same overall length of a P365XL slide. This was an ideal choice since it would make the gun even flatter shooting and still have higher muzzle velocity with a longer barrel than a standard P365. When installed on a P365XL grip module, it also fits exactly as if it was an XL slide and looks fantastic.
After testing with the PMM comp, I’ve found it is one of the most effective small comps I’ve ever used on a small pistol. It’s so effective in fact that you cannot use it with a standard P365 recoil spring and you will get failures to eject. Thankfully, DPM Systems released a guide rod designed to reduce recoil that you can change spring weights on allowing you to tune the recoil spring weight for the comp.
For selecting a slide, I turned to Norsso. I’ve been following them for several years now as they make great slides for a bunch of firearms including Glock and Sig. I chose the Reptile slide, particularly for its aggressive appearance and the forward and rear serrations that are easy to grip even if your hands are soaking wet. I’d previously run these on Glocks and have been very pleased with the quality and appearance. On my P365, the Reptile slide looks as if it was made to go with the PMM comp, and together they have a really cool appearance. The Reptile slide also gives me one of my key requirements for this build: the option of optic cut that lets me keep real rear irons.
Sighting In
For sight selection, I wanted true backups with tritium that I could co-witness with a red dot. The little notch in micro foot-print red dots just doesn’t cut it for me. I went with Ameriglo suppressor height tritium sights. The real rear irons help acquire the target without hunting for the red dot even in low light and are precise enough for even distance shooting with the compact P365. The suppressor height is perfect for co-witnessing paired with the Holosun 507k. Previously I had used the Shield RSM, but the 507k since you can choose a precise dot or the dot and large circle for fast defensive shooting. Additionally, being able to manually set the brightness was something I wished for previously as the RSM. The auto-bright is nice in a lot of ways, but in bright daylight, I found it often didn’t adjust bright enough. This comes with the tradeoff of a shorter battery life since it’s not dimming automatically, but the 507k makes up for this with a pullout battery tray, making it easy to replace without losing zero.
Finding A Holster
With the degree of customizing, I did; I needed a holster to match it. It was actually very simple, I shipped an extra adapter from Tactical Development to my friend who owns Saek Holsters. With the adapter in hand, he made a great fitting holster and sidecar mag carrier in my custom Kydex options with my preferred carry clips. Even with custom fitting, pricing was more affordable than the competition and the quality of the holster is excellent. And one of the best parts, I didn’t have to modify someone else’s holster myself after getting it. All the previous holsters I’ve had to modify for odd components as well as general fit and retention. Saek’s Holsters nailed all of this right from the beginning.
Running The Gun
You might think with selecting so many different manufacturer’s parts for this build I would need a lot of break-in or fitment to get everything running right, but that was not the case. My very first P365 required a few hundred rounds to break in, but they really have the specs dialed in now and the manufacturers’ parts I chose are premium examples. The only issue I ran into was due to the PMM compensator being too effective for a standard recoil spring. I quickly solved this with the DPM spring kit. I found the longest spring they include is ideal for use with 115gr target loads up to 124gr +P defense loads. A lighter recoil load will not properly cycle, but since this is an EDC, I don’t intend to use it for anything other than full power loads. Standard 115gr range ammo runs great for practice and my preferred defense load of Speer 124 +P Gold Dots runs flawlessly.
On the range, this is my favorite shooting carry pistol yet. The combination of parts I put together resulted in the flattest shooting carry gun I’ve ever shot. Looking at high-speed video from shooting it, the muzzle rises less than half an inch thanks to the compensator, gas pedal, and weight balance. Recoil mitigation on the gun is simply phenomenal and rapid follow-up shots are blazingly fast.
As I mentioned before, the trigger on the custom works FCU is a significant upgrade from the standard trigger. The break is much cleaner and has a better reset than the OEM trigger. Unlike my other P365 triggers, I haven’t needed to do any modification to the custom works FCU for it to fit my taste for an EDC. I’m pretty picky about my triggers so this was a nice surprise as I expected to change both the trigger shoe and spring, and do some polishing in the beginning.
With the extras I have on it, you might expect the gun in a holster to print. That is definitely not the case. Where the extra width is from the gas pedal and light, is actually where many AIWB holsters add material to aid in pulling the grip against your body. Saek Holsters did a perfect job customizing it for my configuration so draws and re-holsters are quick and smooth and retention is perfect. As a thin guy, some AIWB holsters have a tendency to make me look pregnant, but this one disappears perfectly and is comfortable for all-day wear.
In spite of the compact design, this is also an extremely accurate pistol. My groups are very tight with it and I routinely practice shooting with both the red dot and irons in case the battery is ever dead when I need it. Both are easy to be accurate with and I even push it out to 100 yards on IPSC silhouettes which is a breeze with this setup. For quick shots in close, the circle reticle on the Holosun 507k is an awesome choice and the dot in the middle is fine enough for long accurate shots. Also, since you can set the brightness it is easy to find a preferred setting that will be visible even in bright daylight, but not too bright indoors.
What’s Next?
Once you have the itch to build your own, there is always something new to put together. Just like when the AR revolutionized the ability of the common firearm owner to customize their rifles how they want, the P365 has given them the even easier capability to do so for their EDC. Back in the day, it was joked that the AR was “Barbie for Men” since you can dress it up however you want. The P365 is just as customizable and easier for the common owner to change. Right now I have my eye on several new products in development so I’m already considering parts for my next build. The biggest teaser on this front is new grip modules that incorporate many of my favorite features discussed above in the grip module without needing additional accessories.
While I was writing this article, Sig released the P365 X-Macro. The X-Macro gives similar capability to what I’ve built, though not quite as refined. I might consider a customized X-Macro grip module down the road, but I will probably stick to the XL size for easier concealment since the longer grip is more likely to print. Also, the slide comp on the X-Macro is a big step up from a stock XL for recoil management, but by simple physics, slide comps aren’t as effective as true barrel comps, especially ones like the PMM comp. I will definitely be getting the new 17-round mags for backups, however. Tactical Development is already working on baseplates for these to fit perfectly with the P365XL frame so there won’t be an unsightly and uncomfortable gap on the mag sticking out.
Another new piece of gear I’m considering is the new Holosun EPS Carry. It’s basically the same as the 507k I’m running except it has an enclosed emitter. That is an ideal upgrade for a carry gun since it will keep lint from building up on the screen or blocking the emitter during daily carry.
The great thing about the P365 platform is there are so many innovative companies making new accessories for it. If you want a carry gun that you can truly make your own, the P365 has endless possibilities. Beware, it’s addicting, but there’s no limit to what you can build in today’s market.
| Component | Manufacturer |
| P365 FCU | Sig Sauer Custom Works |
| Firing Pin & Slide Completion Kit | Sig Sauer |
| P365XL Grip Module Cerakoted & Stippled | Lake City Gripworks |
| P365 Reptile Slide Optic Cut | Norsso |
| P365 JTTC Micro Comp and Barrel | Parker Mountain Machine |
| Extended Magazine Release | Armory Craft |
| Tritium Suppressor Height Sights | Ameriglo |
| Recoil Reduction System | DPM Systems Technologies |
| Pro Ledge Tactical Application Rail | Tactical Development |
| 507K Reflex Sight | Holosun |
| TLR-8G Bright Compact Light & Laser | Streamlight |
| Sloppy Seconds IWB Holster | SAEK Holsters |
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If you were worried about anything more than a G43 printing, then the Macro is not for you. The heel end of the grip is MUCH longer than the XL. I laid my macro up against my G19 and the grip is longer than that.
Re the PMM comp. I bought one in December and have about 1000 rounds through the gun with it and have zero malfunctions that weren’t related to ammunition. I’m running the stock recoil spring assembly. Maybe I didn’t have trouble because the gun (and recoil spring) already had 5000 rounds through it before I installed the comp. But either way, I’ve never heard of needing to install a softer recoil spring for the PMM comp. Unless all you shoot is Winchester White Box. Ha.
Ok Great article the only thing I dont see On the list or did you mention is the Magazines used, are they stock? If not who makes them you did mention something in the after thoughts of a 17 round with filler pieces as back ups
Turn an actual defensive handgun into a race gun. Smh.
That’s why I left IPSC for IDPA years ago. To each their own, 8 suppose, but that is a LOT of money to fix…..nothing.
In December I did a 2 day defensive pistol class with my 365. I shot about 1400 rounds and by the end of the class my forearms were shot from holding on.
At one point I got to shoot the instructors gun with a PMM comp and the difference was enormous. I also found that adding a small mag extension that allowed me to get my pinky on the grip made a huge difference.
What I learned in that class was invaluable. I now have a PMM comp and a small mag extension on an otherwise stock gun and hits made it MUCH easier for me to shoot the gun fast with accuracy. The PMM comp was so small that the gun even fit in my existing holster and did not protrude past the end of it. So it’s added zero practical bulk to the gun/holster system.
Also, it’s still cheaper to buy a whole gun and just add the PMM barrel/comp. Unless you want it all tarted up like the author did.n. But that’s not necessary to get the gun functioning great and easy to shoot fast. My 365 with the PMM comp is easier to shoot fast than my G19.
+1 to all comments below. You’re better suited to call it your range or home defense gun, but not an EDC gun. And the use of “addictive” certainly fits the narrative just as it does for those who go overboard with Botox injections – freakish and costly. I’ll stick to the stock XL platform tucked IWB, hoping I never have to use it. But should that day ever arrive, I’ll know the gun will function just as Sig designed it to W/O modifications.
That’s your idea of a carry pistol? Lol. That’s the most trying-too-hard douchbag gun I’ve seen in a while.
Gear fetishists. I know nothing about the authors skill level and I’m not saying he’s unskilled.
But the new gun owners who aren’t actually shooters yet, are buying and customizing the 365 in droves. It’s pathetic actually. Everyone wants the cool guy gun, a tarted up 365. $1500 into a plastic carry gun is insane.
Especially when it functions flawlessly totally stock. The stock 365 trigger has a great soft rolling break that you want when you are shooting fast. You don’t want a crisp break unless it’s a 2 lb trigger, and a 2 lb trigger is inappropriate for a carry gun.
I used to own a Brazos Custom 2011. It had a crisp 1.5 lb trigger. It was great to shoot fast. But I’ve also owned 1911s with crisp 6 lb triggers, and the sig trigger is superior to those when shooting fast. Slow fire bulls eye, it’s a different story. But the lack of stacking before the gun fires facilitates fast, smooth shooting.
What was the total $ when all was said and done?
Where’s the bipod? You’ve got everything else on there but that.
Thank you for the very informative article. I enjoy firearm customization as well, especially EDCs. My only concern is that if we ever had to use a customized firearm in a defensive capacity, would the extent of our pistol’s customization work against us in court? In these highly litigious times in which an understanding of firearms seems to be more the exception than the norm, I’m envisioning a lawyer (criminal/civil) painting a picture of you or I as being someone who went out of our way to use our firearm when perhaps nonviolent deescalation was possible, or perhaps attempting to establish that firearm customization (and ammunition selection) constitutes intent to make the weapon more lethal.
Perhaps someone with legal knowledge/experience could comment on this.
No thermal or 37mm flare launcher? Dude, the 365’s are the best concealed carry guns there ever were WITHOUT modification. No way I’d trust that pile of….stuff. you said it runs “great” with 115 ball for practice and “flawless” with 124 hollowpoints…that leaves me feeling you have hiccups with 115 practice ammo. That’s unacceptable, you know how many times my stock 365 has jammed in 4000 or so rounds? I’ll let ya know if it ever happens. That thing is hideous and likely untrustworthy. You’d have been way ahead to stick with a stock gun and use all that wasted money on 5 or 6 cases of ammo to train with. Oh and is that your holster printing in your back?? It’s sure looks like it. Only visible from maybe 2 football fields away.
David M, stop worrying, a clean shoot is a clean shoot. You either f’d up or ya didn’t. If Michael Myers comes through your door with a butcher knife and his mask on, does it matter if you beat him to death with a T-Fal factory frying pan or a cast iron homemade one you got at a blacksmith place on vaycay?? Doesn’t matter does it….he tried to off you and you took care of it. Nobody cares what pan you used. Same with guns and ammo.
He thinks the gun looks “cool”. I think it looks like a junk pile.
Every one to their own taste.
Exactly. If he shoots it well and it functions reliably, I see no issue with it.