Introduction of Holosun 507C and Holosun 407C
Holosun 507C and Holosun 407C are among the most popular open reflex red dot sights on the market. They are not the lightest red dots around, but the durability and robustness more than makeup for it. Somewhere at the beginning of 2020, Holosun released the second generation of these models with the V2 mark next to the name. Soon after, they released the third generation models marked 'X2'.
Watch our Holosun Reflex HS507C video
Interested in Holosun 507C Reflex Red Dot?
Holosun 407C and 507C (gen I)
The first-generation models had small buttons for the illumination adjustment. These were somewhat inconvenient to use, especially when shooting – while looking at the target, the shooters found it difficult to locate and press the desired button as quickly as they wanted to. On top of that, they were placed horizontally, making it difficult to remember the exact position of the ‘–‘ and ‘+’ button.
The old models had a battery compartment on the bottom. The user had to remove the red dot sight from the firearm to access it, not to mention that it had to be re-zeroed once it was put back on. The battery compartment had to be opened with a special tool, and the whole process was kind of clumsy.



HS507C-RD Gen II (left) and Gen I (right)
Holosun 407C and 507C V2 (gen II)
Holosun listened to their customers and released the second-generation (V2) models with bigger buttons that were easier to locate. Furthermore, they placed them vertically – having the ‘+’ button above the ‘–‘ is much more intuitive and simpler to memorize. They moved the battery compartment to the side, making it easier to change the battery since no removal of the sight from the firearm was needed. Re-zeroing was thus also avoided. Because the compartment has been moved upwards where there is less space, Holosun had to change the battery standard from CR2032 to CR1632 battery.



HS507C-RD Gen II (left) and Gen I (right)
Holosun red dot 407C and 507C X2 (gen III)
In 2020, Trijicon sued Holosun for alleged patent infringement which concerned 407C and 507C V2 models among others. When the lawsuit was settled, Holosun was obliged to remove the V2 models from the market. They introduced the third generation of the 407/507C series, marking it 'X2'. The buttons' design of the X2 models is the same as on the first-generation models. They retained the side battery compartment (CR1632) and added another feature that the first- and the second-generation models lacked – a button lock mode.



Holosun's 507C X2 red -dot
Around a half year after the X2 models were put on the market, Holosun stopped shipping them with a mount for the Picatinny platform. It has to be purchased separately from then on.



Holosun's 507C X2 red -dot
Watch our Holosun Reflex HS507C RD X2 video
Interested in Holosun 507C-GR X2?
Holosun open reflex sight models
Currently, there are four models available:



HE407C-GR V2 red -dot
Interested in Holosun 407C-GR X2 Reflex Red Dot?
Holosun's models with ‘4‘ as the first digit feature a 2 MOA circle dot reticle. Models with ‘5’ as the first digit feature a switchable reticle – the user can toggle between 2 MOA dot, circle dot, and circle only.
RD means red illumination. GR stands for green illumination - green dot sight.
C stands for ‘solar cell’.



HE507C-RD V2 red - dot
Interested in Holosun 407C Reflex Red Dot?


General properties of 507C and 407C MOA dot sight
Holosun used the same form factor for the first, second, and third generations. CNC-milled 7075 aluminum is used for the housing. The devices weigh around 40 grams.
The solar panel on top is extremely useful as the illumination is powered by solar energy even if the battery dies. You can also use solar mode even while the battery is working to preserve battery life.
The drain holes prevent water from accumulating in the place between the diode and the lens. Open reflex sights are not meant to be used in rain, but if you are caught in bad weather for some reason, you will not have to flip the red dot sight to get the water out.



HE507C-RD V2 red dot sight
Does Holosun 507c fit RMR cut?
Models from all three generations of Holosun's 507C and 407C sights feature the Trijicon RMR footprint for mounting on a pistol.
Need more information about footprint on 507C and 407C?



HS507C-RD Gen II (left) and Gen I (right) – Footprint



Holosun 507C X2 red - dot – Footprint
The elevation and windage adjustment screws can be rotated with an included tool. A click equals 1 MOA, which translates to approx. 1.5 centimeters at 50 meters.
If you leave the red dot sight stationary, it goes into sleep mode thanks to the Shake Awake function. When you move it again, the illumination turns back on in an instant.
All the sights are waterproof with an IPX7 certification.



HS507C-RD V2 red dot sight
Conclusion
Let us take a look at how the Holosun red dot 407C vs 507C models have changed throughout the years.
407/507C (gen I) | 407/507C V2 (gen II) | 407/507C X2 (gen III) | |
Battery compartment | On the bottom, CR2032 | On the side, CR1632 | On the side, CR1632 |
Buttons | Small, placed horizontally | Big, placed vertically | Small, placed horizontally |
Button lock mode | No | No | Yes |
Picatinny mount included | Yes | Yes | Only at the beginning, now it must be purchased extra |
The prices range from 290 to 410 €, depending on the model. These are a great choice if you are looking for a robust open reflex sight.



HS507C-RD V2 red MOA dot



HE407C-GR V2 MOA dot



HE407C-GR V2 red -dot
Picture Gallery






Awesome review. Thank you for sharing this information. I know which one I think I am going to get for my carry gun.
Thank you information is power I feel much smarter after learning about foot prints more confident you don't want to torque a sight down when the pins are longer than the sockets' again thanks Bob
Thank you for your kind comment, we are glad that the article has been helpful to you.