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  • Post last modified:October 22, 2023

In this article, I will compare the Holosun 507C and the Holosun 507K, two red dot sights. I will share my experiences and provide insights into what I liked and didn't like about using them at the shooting range and in everyday concealed carry situations.

To assess their durability, I deliberately subjected them to various tests, including dropping them, scraping the lens on tough surfaces, and exposing them to mud. While some of the outcomes were as expected, there were also surprising results. Through this comparison, my goal is to help you determine the best red dot sight to suit your specific needs.

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Holosun 507C VS 507k - Differences

The Holosun 507K is designed for subcompact handguns featuring the RMSc mounting footprint. The Holosun 507C is a full size micro red dot sight that features the RMR footprint for full size handguns.

holosun 507c vs 507k
holosun 507c vs 507k

Both red dot sights offer an impressive battery life of up to 50,000 hours and come equipped with Holosun's multi-reticle system. Additionally, they both support the ACSS Vulcan reticle (available separately).

One notable difference is that the Holosun 507K features a special cutout that allows for co-witnessing with a small rear sight notch, a feature not present in the 507C.

holosun 507k vs 507c
SpecsHolosun 507C X2Holosun 507K
Window Size0.63x0.91"0.58"x0.77"
Material7075 T6 aluminum7075 T6 housing+Anodized
Reticle2 MOA dot size+32 MOA Ring2 MOA+32 MOA Ring
BatteryCR1632, Side loadingCR1632, Side loading
Construction7075 T6 housing+Anodized7075 T6 housing+Anodized
Battery Life50,000 hours50,000 hours
Body Dimension1.78" X 1.15" X 1.15"1.6" X 0.98" X 0.95"
Brightness Setting10 DL&2 NV10 DL&2 NV (Features Lockout Mode)
Adjustment1 MOA/Click1 MOA/Click
Weight1.5 oz1 oz

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Holosun 507C VS 507K Footprint

holosun 507k vs 507c

The Holosun 507C is primarily designed for full-sized pistols and follows the RMR footprint, whereas the 507K is designed for subcompact pistols and follows the RMSc footprint. Their main distinctions are in optic size and field of view.

507C VS 507K Field Of View

507k vs 507c

The Holosun 507C indeed boasts a larger lens window when compared to the Holosun 507K. The speed at which you can spot the dot largely depends on your practice and the grip angle of your handgun, which influences the alignment of your line of sight with your eye.

If your main goal is to find an optic that allows you to quickly acquire and reacquire the dot after each shot, I recommend taking a look at the ACSS Vulcan reticle below, which is provided by both optics.

Reticle Options

Both optics feature Holosun's signature multiple reticle system, which features:

difference between holosun 507c and 507k
holosun 507c vs 507c x2
  • 2 MOA center dot only - For precise aiming without a cluttered field of view
  • 32 MOA ring only - For fast target acquisition up close and for shooters with astigmatism
  • Combined - Nice to have for PCC use, but nothing to dislike either
holosun 507k vs 507c
holosun 507c vs 507k

Another option that is my favorite is the ACSS Vulcan reticle, which features a large outer 250 MOA ring to help guide the shooter's eye back to the center when shooting handguns. Both Holosun 507C X2 and Holosun 507K X2 offer ACSS models.

Weatherproof Performance?

In terms of weatherproof performance, both the Holosun 507K X2 and Holosun 507C X2 are not completely weatherproof. In regular usage, these optics perform exceptionally well, and there are no complaints.

However, when exposed to rainy or sandy conditions, they can still function, but if water droplets make their way to the inner part of the glass, it becomes challenging to clean them without leaving some form of fingerprint smudge.

hs507c vs hs507k

If the optic is accidentally dropped into mud or wet snow, it can completely obstruct the LED emitter, and cleaning the optic requires both a tool and a Q-tip.

Battery Life

Both optics are powered by a single CR1632 battery, providing more than 50,000 hours of functionality without needing a battery replacement. So far, I haven't had to replace the battery, so it hasn't been a pressing concern.

507c vs 507k

The Holosun 507C X2 has transitioned from a bottom battery loading design to a side tray design. This allows users to easily replace the battery without removing the sight or requiring re-zeroing.

Additionally, the 507C X2 model features a solar panel on top, a feature absent in the 507K model. 

holosun 507c x2 solar panel

While having a solar panel can be convenient for outdoor use, it may not be relied upon indoors as it only functions in sufficient light, and you need to press a button if the red dot suddenly turns off.

holosun 507c vs 507c x2

Both optics also incorporate Holosun's ShakeAwake motion sensor technology, which essentially turns off the sight when it's not in motion and reactivates it when any movement is detected. While this is a well-designed feature, it may have limited practicality for concealed carry use, as the optic is typically mounted on a person who is constantly moving.

Is The Holosun 507C Discountinued ?

The older 507C V2 has been discontinued, and the new model is the Holosun 507C X2. It has been redesigned to feature side loading battery tray, a new body finish,  and it has smaller adjustment buttons.


  • The 507C is for full size pistol use
  • The 507K is for sub compact pistol use
  • The 507K has rear notch cutout for front sight co-witness if the dot disappears.
  • Both red dot sights are open emitter optics that are prone to attract dirt and they are not weatherproof. However, under non rainy conditions, they are great
  • Side loading battery is convenient for battery swap without sight removal