Suppressing The SIG P365: A Complete Guide to Silencing Your Handgun

The SIG SAUER P365 changed the game for concealed carry when it was released in 2018. It’s compact, high-capacity, and built to perform far above its weight class. But here’s something most folks don’t realize: you can suppress it–really easily. And not only is it possible—it’s practical, surprisingly effective, and honestly, a lot of fun. Whether you're rocking the standard P365 or the XL variant, turning this micro 9mm into a whisper-quiet sidearm is easier than you might think. In this guide, we’ll walk you through everything you need to build a reliable, suppressed P365—from threaded barrels and boosters and top suppressor picks, sight upgrades, and ammo tips. Let’s get quiet!

• Why Suppress the SIG P365?

• Getting a Threaded Barrel for Your P365

• Booster Devices Matter (and Why You Need One)

• Best Suppressors for the SIG P365

• Upgrading Your Sights for Suppressor Use

• Subsonic Ammo: Does It Matter?

• Step-by-Step: Suppressing Your SIG P365

• Final Thoughts & Quick Tips

The P365 is already one of the best concealed carry pistols on the market—but suppressing it takes things to a whole new level. While some folks think suppressors are only for full-size pistols or tactical setups, the truth is: any gun becomes much more fun when you run it suppressed, so if it gets you shooting and practicing more while also saving your ears, its a great upgrade.

Why it’s worth doing:

Quieter shots: Save your hearing, skip the ear pro, and keep the range neighbors happy.
Less recoil: A suppressor tames the snapiness of the small handgun, making it smoother and more controllable.
More fun to shoot: You'll want to train more, shoot more, and enjoy your range sessions longer.

A suppressed P365 won’t just turn heads at the range—it’ll also help you shoot better and train smarter. Whether for enhanced range days  or as a personal defense setup that won’t destroy your ears, a Sig P365 with a silencer is an awesome pistol.

You can’t run a suppressor without a threaded barrel—it’s the foundation of the entire setup.

JK Armament makes one of the best drop-in threaded barrels for the P365 and P365XL, and we have them on the shelf!  They're nitride-finished for durability and has the standard 1/2x28 thread pitch, which means it’ll pair with most common 9mm suppressors without needing any weird adapters.

Quick tips:
Drop-in installation – no fitting or gunsmithing needed.
Options for both P365 and P365XL – same great quality, ready to make either model suppressor ready
Built tough – black nitride coating resists wear, corrosion, and fouling.

If you’re going suppressed, start with a JK threaded barrel. 

This part trips up a lot of first-time suppressor buyers but its actually pretty simple. The P365, like most modern pistols, uses a Browning tilting barrel design—meaning when you fire, the barrel and slide move and the barrel tips upward to allow the firearm to cycle and a new round to feed. If you bolt a heavy suppressor directly to that system, it can’t move like it’s supposed to. That’s where the booster (or Nielsen device) comes in.

A booster is a spring-loaded coupling that lets the suppressor “float” for a split second during recoil, ensuring the pistol cycles reliably. The booster decouples the weight of the silencer from the barrel, allowing it to move and tilt as designed. Boosters are generally required for pistol silencers to cycle corrrectly, and most pistol sielncer will include a booster with the can so you'll be good to go. 

You’ll need:
A suppressor and a booster housing
A 1/2x28 piston (this is the piece that screws onto your barrel thread)
Periodic cleaning—boosters can get gunky over time

Running your can without a booster will likely result in failures to feed, stove pipes, or your slide not fully cycling. Some silencer that are extremely lightweight can cycle without a booster, but this is uncommon. 

You’re suppressing a small gun, so you’ll want a suppressor that doesn’t turn it into a boat anchor. Fortunately, Silencer Shop has several 9mm suppressors that pair perfectly with micro pistols thanks to their light weight, modularity, and compact size.

The Rugged Obsidian 9 has been a fan favortie for years, and for good reason. It is incredibly durable and reilable, sounds great on a variety of weapons, and the modularity allows you to tune it to your pistol. 

• Run it long for maximum quiet or short for better balance.

• One of the quietest 9mm cans out there—great for subsonic ammo.

• Full-auto rated and built to last a lifetime.

The Q Erector 9 is a fully modular 9mm suppressor that excels on 9mm pistols due its flexibilty and lightweight design. 

• Incredibly modular—configure it down to just a few baffles.
• LArge internal volume allows for awesome sound reduction.
• Lets you fine-tune your length, weight, and backpressure.

The JK Armament CCX 9 is an ideal suppressor for small 9mm pistols. It is configurable in length and weight, and is so small that it does not require a booster to run correctly. 

• No booster needed, perfect for concealed-carry pistols.
• Fully modular system built for everyday use.
• Lightweight, rugged, and great sound suppression in a small package.

All three suppressors bring down the decibles and will run great on the Sig P365. They work with 1/2x28 threaded barrels, and have stellar reputations in the suppressor community. You really can’t go wrong here—it just comes down to your balance between size and suppression.

The moment you screw a can onto the front of your pistol, you’ll notice your factory sights vanish behind it. If you plan on actually aiming (and you should be), you’re going to want either suppressor-height iron sights or a red dot.

Many modern P365 and P365XL models come optics-ready, which makes this upgrade a breeze.

Best Suppressor Height Optics for Sig P365:

• SIG ROMEO-X Compact Red Dot – Purpose-built for SIG pistols with excellent glass and battery life.
• EOTECH EFLX – Bright, crisp, and sits tall enough to co-witness with most suppressors.

Red dots give you better target visibility and faster follow-up shots—especially handy on small guns like the P365 where sight radius is limited to begin with.

It absolutely does—especially if your goal is to make the gun as quiet as possible.

Supersonic rounds create a sonic crack when they break the sound barrier (about 1,100 fps). Subsonic rounds stay below that speed, so all you hear is the muffled report of the pistol.

What to look for:

147gr or heavier 9mm – These are usually subsonic by design.
Stay away from +P – Less gas = less blowback and less sound. High pressure rounds will be faster and louder.
Reliable cycling – Test before you trust.

That said, the P365 has a short barrel—so even some lower pressure 124gr loads will dip below supersonic speeds. But if you want guaranteed quiet, stick with 147gr and up.

Installing a suppressor setup on the P365 isn’t rocket science—but a good walkthrough helps.

How to get there:

1. Unload and clear your pistol. Safety is non-negotiable.

2. Field strip the slide. Swap in your threaded barrel.

3. Assemble your suppressor with a booster and the correct 1/2x28 piston.

4. Thread on the suppressor until it’s hand-tight—no tools needed.

5. Function test by racking the slide and dry firing (with snap caps).

6. Hit the range and test with a few ammo types—note which ones cycle best.

If everything works like it should, you're good to go.

Suppressing the P365 takes this already excellent carry pistol and gives it an edge—whether for training, carry, or just plain fun. It’s quiet, soft-shooting, and refreshingly practical. With the right setup, you’ll wonder why you didn’t do it sooner.

• ✅ Get a  threaded barrel

• ✅ Choose a suppressor with a booster and 1/2x28 piston

• ✅ Consider modular cans like the Rugged Obsidian 9 or JK Armament CCX 9

• ✅ Upgrade your sights or run a red dot

• ✅ Shoot 147gr subsonic for maximum suppression

Want to silence your SIG? Silencer Shop makes it simple—and we’ve got the gear to do it right.