The SIG Sauer P365 has become one of the most popular concealed-carry pistols out there, and a big part of its appeal is how much capability SIG managed to fit into such a compact package.
If you’re looking to add an Osight red dot to your P365, this guide will walk through every Osight optic that will fit, along with the footprint and mounting details you need to know before choosing one.
Which SIG models does this apply to?
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All optics-ready SIG P365 models |
P365, P365X, P365XL, P365 X-Macro, P365 AXG Legion, P365-380, P365 Luxe |
Which Osight optics do we recommend for the SIG P365?
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RMSc |
Why Consider an Osight Red Dot?
Osight has made a name for itself by offering pistol red dots without pushing the price into premium-optic territory. They’ve also been pretty willing to try things that are a little different, with features like rechargeable optics with magnetic charging covers, multiple reticle options, enclosed emitter designs, and newer housing materials like OAL.
For the P365, Osight offers a few compact options that make a lot of sense for the size of the pistol. You can choose between open and enclosed emitter designs, different reticle styles, and either rechargeable or replaceable-battery models depending on what you prefer.
Overall, Osight is a good option if you want a compact pistol optic with modern features at a more approachable price, whether your P365 is set up for concealed carry, range use, or everyday shooting.
What optics footprint is the SIG P365?
The optics-ready SIG P365 family uses the compact RMSc footprint. That means the RMSc-footprint Osight optics covered in this guide can mount directly to compatible optics-ready P365 slides without an adapter plate.
One thing that can make P365 fitment a little confusing is that SIG has made several running changes over the years. Earlier P365 optic-ready slides use M3 mounting screws, while newer versions can use M4 screws. The footprint is still the same, the difference is the mounting hardware you’ll need. You may also see newer P365 models advertised with SIG-LOC. SIG-LOC adds a new mounting system for compatible SIG optics, but SIG designed those slides to remain compatible with traditional RMSc optics as well. So even though the mounting system has evolved, all RMSc optics compatibility is still there.
What adapter plates exist for the SIG P365?
The good news here is that you won’t need an adapter plate for any of the Osight optics covered in this guide because the compatible Osight models use the RMSc footprint.
Best RMSc-Footprint Osight Optics for the SIG P365
1. Osight SE Red & Green Dot - Direct Fit RMSc Enclosed Carry Dot
Buy the Osight SE At The Best Price
The Osight SE is a compact enclosed-emitter pistol optic designed for everyday carry, concealed carry, home protection, and defensive use. Its fully enclosed design protects the emitter from dirt, moisture, lint, and debris, helping the optic remain dependable in harsh conditions or during daily carry.
Unlike Osight models that use a magnetic charging cover, the Osight SE is powered by a side-loading CR1620 battery. This allows the battery to be replaced without removing the optic or disturbing your zero. Battery life is rated for up to 75,000 hours at brightness setting three.
The Osight SE is available with either a 6 MOA dot or a multi-reticle system featuring a 2 MOA dot and 32 MOA circle. Both reticle options are offered in red or green. The optic also includes eight daylight brightness settings and two night vision settings.
Its housing is made from durable 7075 aluminum, while the aspherical lens is designed to provide a clear, distortion-free sight picture. The optic uses the compact RMSc footprint and weighs just 0.97 ounces, making it a strong option for slimline and concealed-carry pistols.
Who is it for? The Osight SE is best for shooters who want a compact, enclosed optic with replaceable batteries, multiple reticle choices, and strong protection against the debris and moisture commonly encountered during everyday carry.
2. Osight S Red Dot - Enclosed RMSc Optic with Rechargeable Battery
Buy the Osight S At The Best Price
The Osight S is a compact enclosed-emitter pistol optic designed for those who want the added protection of an enclosed design combined with a rechargeable power system. It is very similar in size and overall design to the Osight SE, but instead of using a replaceable side-loading battery, the Osight S is recharged using Olight’s magnetic charging cover.
The charging cover features an integrated battery display that shows the remaining battery level of both the optic and the cover. A fully charged cover can recharge the optic approximately three times before the cover itself needs to be plugged in. The optic provides up to 21,900 hours of runtime at brightness level three while using the 2 MOA dot only.
The Osight S is available exclusively with a red multi-reticle system. You can switch between a 2 MOA dot with a 32 MOA circle, the 2 MOA dot by itself, or the 32 MOA circle by itself. It also includes ten daylight brightness settings and two night vision settings.
The housing is constructed from Olight’s OAL material, which the company claims is 19% harder than 7075 aluminum and offers strength comparable to titanium while maintaining a lightweight design. The optic weighs just 0.97 ounces.
Who is it for? The Osight S is best for those who want a compact enclosed optic with a rechargeable battery system and do not want to purchase or replace disposable batteries.
3. Osight K - Best Budget RMSc Red Dot
Buy the Osight K At The Best Price
The Osight K is a compact open-emitter pistol optic designed as the most budget-friendly option in Osight’s RMSc-footprint lineup. It shares the same general size and window dimensions as the enclosed Osight SE, but its open-emitter construction keeps the design simple and affordable.
The Osight K is available with a 6 MOA dot in either red or green. The larger dot is easy to locate during the draw and works especially well for close-range shooting, concealed carry, and defensive use. It includes eight daylight brightness settings and two night vision settings.
Power comes from a side-loading CR1620 battery. Runtime is rated for up to 63,000 hours at brightness level three. A motion sensor automatically activates the optic when movement is detected and powers it down after three minutes of inactivity to conserve battery.
The housing is constructed from 7075 aluminum and weighs 1.02 ounces, features a 0.83 × 0.55-inch window, and carries an IPX6 water-resistance rating.
Who is it for? The Osight K is best for shooters who want an affordable, lightweight RMSc optic with a simple 6 MOA dot and easy side-loading battery access. It is a strong entry-level choice for concealed-carry pistols, range guns, and anyone who does not need the added protection of an enclosed emitter.
Choosing between Red or Green Reticles
It’s common to go back and forth between red and green reticles, so here are a few practical points to help you decide which one makes the most sense for your setup.
- Green reticles are often easier on the eyes, especially during longer range sessions or extended training.
- Shooters with astigmatism sometimes see a cleaner dot in green. While results vary from person to person, many customers report that a green reticle appears more defined and less “smeared” compared to red.
- Green will not wash out on backdrops like green grass, foliage, or green colors.
- In theory, green dots can have a longer battery life because green is brighter, so for example a green dot on brightness setting 6 may be the same brightness as a red dot on setting 7 - which would save battery life.
If you want to learn more check out our full article about Red vs Green Dot Pros & Cons here.
Choosing between Open vs Closed Emitters
A simple way to think about open versus enclosed emitter red dots is to match the optic to how you plan to run your SIG P365.
If your P365 is going to see a lot of outdoor use in rain, snow, or rough conditions, an enclosed emitter has a clear advantage. The emitter is sealed inside the housing, which helps prevent water, dirt, or debris from blocking the dot when conditions are less than ideal.
For shooters running OWB setups, whether for duty, range time, or general outdoor use, enclosed optics tend to be the safer choice for that added protection and consistency.
If your P365 is primarily carried IWB or used in more controlled environments, an open emitter optic will serve you just fine. They are lighter, simple, and still perform well in most situations, including light weather. Enclosed designs just add an extra layer of reliability when things get messy.
Maintenance is another factor to consider. Open emitter optics can collect dust, lint, and debris over time, especially with daily carry, so occasional cleaning is part of the routine. Enclosed emitters are easier to maintain since the critical components are protected inside the housing.
To learn more about Open vs Closed emitters you can check out our Open vs Closed Emitter Guide here.
How to decide which Osight reticle style is best for you
In this guide we covered a few different reticle options. If you need some help deciding which is best for you here are some of our thoughts on each.
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6 MOA only (K, SE): Is a more user-friendly option that’s easier to pick up on the draw thanks to its larger size. It sacrifices a bit of long-range precision compared to smaller dots, but it’s still plenty accurate for realistic pistol distances. The bigger dot stays fast, clear, and uncluttered, which is why many shooters prefer a 6 MOA dot over multi-reticle systems for simplicity and speed. |
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MRS Reticle: (32 MOA Ring + 2 MOA Dot: S, SE) or This option combines a small center dot with a large 32 MOA outer ring, giving you the best of both worlds. The center dot allows for precise aiming, while the outer ring makes dot acquisition fast and intuitive. The biggest advantage of MRS is flexibility. You can run the dot only, the ring only, or both together, letting you tailor the reticle to your shooting style and stick with what feels best. |
Conclusion
The SIG P365 is an excellent concealed-carry platform, and its compact RMSc optic cut gives you solid Osight options without needing to add an adapter plate.
The Osight SE is a great choice if you want a compact enclosed emitter with a traditional replaceable battery. The Osight S gives you a similar enclosed setup but adds Osight’s rechargeable magnetic charging system. And if you want to keep things simple and affordable, the Osight K gives you a lightweight open-emitter option with a straightforward dot reticle.
Hopefully this guide helped narrow down which Osight makes the most sense for your P365. If you’re still having trouble deciding, reach out to our customer service team and we’ll be happy to help you choose the right optic for your setup.
