Holosun HS503R 2 MOA & 65 MOA Cicle Red Dot Sight with Rotary Switch
The Holosun HS503R is a compact, no-nonsense micro red dot built for rifles and carbines that just needs to work every time. It gives you a sharp 2 MOA dot plus a 65 MOA circle option, so you can switch between fast close-range shooting and a more precise sight picture when you need it. The rotary switch makes brightness changes super quick and simple—no fiddling with buttons—and it’s powered by a long-life CR2032 battery that can run for tens of thousands of hours. Built from durable aluminum with solid mounts included, it’s a reliable, straightforward optic that feels purpose-built for real-world use rather than overcomplicated features.
-Nathan (Technical Advisor)
The HS503R boasts Holosun’s innovative Multi-Reticle System (MRS), offering shooters the choice between a precise 2 MOA dot, a 65 MOA circle, or a combination of both. This flexibility allows for quick target acquisition and adaptability to different shooting conditions. The sight is equipped with 10 brightness settings for daylight and 2 settings for night vision compatibility, ensuring clear visibility in all lighting environments. Its multilayer reflective glass enhances the clarity and sharpness of the sight picture, providing an excellent visual experience.
A standout feature of the HS503R is its remarkable battery life, powered by a single CR2032 battery. The sight can operate up to 100,000 hours on setting 6, thanks to its efficient power management system. The battery is housed in a user-friendly rotary compartment, allowing for quick and tool-free replacement. Additionally, the sight utilizes a rotary switch for easy adjustment of reticle brightness, ensuring rapid and precise control.
This red dot sight is designed with a parallax-free optical system and unlimited eye relief, allowing for rapid target acquisition and accurate shooting without the need for perfect eye alignment. It is IP67 rated, providing waterproof and dustproof performance to withstand harsh environmental conditions. Compact and lightweight, the HS503R features a 20mm window size and weighs only 3.74 ounces, making it an ideal choice for a variety of firearms.
The HS503R also includes both a lower 1/3 co-witness mount (1.63”) and a low mount (.75”), providing shooters with versatile mounting options to suit their preferences and shooting styles.
Dimension (in): 2.73×1.53×1.61
Weight (oz): 3.74
Housing Material: 6061 T6 Aluminum
Surface Finish: MAO
Adjustment per Click: 0.5 MOA
W&E Travel Range: ±50 MOA
Storage Temperature: -40℃~70℃
Working Temperature: -30℃~60℃
Submersion: IP67
Vibration: 1000G
Made from durable 6061 aluminum.
Lightweight (3.74 ounces) and robust design for longevity.
Rubber lens covers for optic protection against damage and debris.
Reticle System:
Holosun’s Multi-Reticle System (MRS) offers versatile aiming options.
Includes a 2 MOA dot, a 65 MOA circle, and a combination of both.
Facilitates quick target acquisition and adapts to various shooting conditions.
Brightness Settings and Optics:
10 daylight brightness settings.
2 settings for night vision compatibility.
Multilayer reflective glass enhances clarity and sharpness of the sight picture.
Battery Life and Management:
Powered by a single CR2032 battery.
Long battery life up to 100,000 hours on setting 6.
Rotary battery compartment allows for easy and tool-free replacement.
User-Friendly Features:
Rotary switch for simple adjustment of reticle brightness.
Parallax-free optical system with unlimited eye relief for rapid target acquisition.
Designed for accurate shooting without perfect eye alignment.
Environmental Durability:
IP67 rated for waterproof and dustproof performance.
Withstands harsh environmental conditions.
Compact and Mounting Options:
Compact design with a 20mm window size.
Includes a lower 1/3 co-witness mount (1.63”) and a low mount (.75”).
Versatile mounting options cater to different shooting preferences and styles.
- Lower 1/3 Cowitness Mount
- Low Profile Mount
- T10 L Key
- Rubber Cover
- User Manual
- CR2032 Battery
- Lens Cloth
1. What reticle does the HS503R use?
It uses Holosun’s Multi-Reticle System: a 2 MOA dot, a 65 MOA circle, or both together.
2. What is the rotary switch for?
It replaces traditional buttons and lets you quickly adjust brightness or settings by turning a dial instead.
3. Is it good for AR-15 style rifles?
Yes, it’s designed specifically for rifles and carbines using a Picatinny rail system.
4. How long does the battery last?
Up to around 50,000–100,000 hours depending on settings and brightness level.
5. Does it have night vision settings?
Yes, it includes low brightness modes compatible with night vision devices.
6. What’s the point of the 65 MOA circle?
It helps you acquire targets faster at close range and can also act as a rough reference for holdovers and ranging.
7. Is it durable?
Yes, it uses a 6061 aluminum housing and is built to handle recoil, weather, and hard use.
8. Does it come with mounts?
Yes, it typically includes both a low mount and a co-witness style mount for different setups.
9. Is it parallax free?
Yes, like most modern red dots, it’s designed for parallax-free shooting with unlimited eye relief.
10. What’s the main advantage of the HS503R?
It’s simple, rugged, and fast to use, with a clean reticle system and an easy rotary control that makes adjustments quicker under stress.
- Holosun 10 years / product lifetime warranty. Read more here