• Post author:
  • Post last modified:April 28, 2023

In this article, I will compare two red dot sights - the Holosun 507C vs Holosun 507K. I will share my thoughts on what I liked and didn't like about them when I used them at the shooting range and for concealed carry in regular situations.

To see how tough they are, I dropped them, I racked the lens on hard surfaces, and I put them in some mud. Some of the test results were expected, while others were not. I hope my comparison will help you decide which red dot sight is best for you.

What Is The Difference Between Holosun 507C and 507k?

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.

shooting sig p320 with holosun 507c
holosun 507k x2 on hellcat pistol

Both red dot sights offer up to 50,000 hours of battery life and Holosun's multi reticle system as well as the ACSS vulcan (Sold separately). In addition, the Holosun 507K features a small notch rear sight cut out for co-witness that the 507C doesn't have.

holosun 507c x2 vs 507k x2
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

See Updated Product Test Progress & Exclusive Deals

Subscribe for ongoing product test results and exclusive coupons emails.

Holosun 507C VS 507K Footprint

holosun 507k vs 507c footprint

The Holosun 507C has been designed for full-sized pistols and features the RMR footprint, while the 507K has been designed for subcompact pistols and features the RMSc footprint.

Their main differences lie in their optic sizes and field of view sizes.

507C VS 507K Field Of View

holosun 507k vs 507c field of view

507C definitely has a bigger lens window than the 507K. As far as quickly finding the dot, it has to do with how much practice you have and your handgun grip angle that puts the line of sight closer to your eye.

If your main goal is to find an optic that allows you to quickly acquire and re-acquire the dot after each shot, please check out below the ACSS vulcan reticle that both optics offer.

Reticle Options

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

32 moa ring only 507c
holosun 507c red dot pov
  • 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 acss long range shot low light
holosun 507c ACSS model

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?

Both Holosun 507K X2 and Holosun 507C X2 are not full weatherproof. Under normal use, these optics are phenomenal, and there is nothing to complain about.

Under rainy or sandy conditions, these optics continue to work, but as soon as water droplet gets on the inside part of the glass, then it's very difficult to wipe it clean without leaving some type of finger smear.

holosun 507k dealing with melting snow

When accidently drop the optic into the mud or wet snow, it can completely block the LED emitter, and you need a tool and a Q tip to clean the optic out.

Battery Life

Both optics use a single CR1632 battery to run the optic, and they both last over 50K hours. So far I have not changed the battery at all, and it has not been an urgent concern.

holosun 507c x2 battery tray access 2

The Holosun 507C X2 has changed the bottom battery loading design to side tray design, so the user can easily replace the battery without sight removal or re-zeroing.

holosun 507c x2 solar panel

The 507C X2 model is equipped with a solar panel positioned on its top, while the 507K model lacks this feature. From my perspective, having a solar panel is a convenient addition, but it's not frequently utilized since it solely functions under ambient light conditions and necessitates pressing a button if the red dot suddenly shuts off.

In addition, both optics feature the Holosun's ShakeAwake motion sensor technology to basically turn off the optic if they are sitting still, and it reactivates the reticle upon any movement.


Even though this is a good design, but it's almost pointless for conceal carry use because it's on a person that's moving around all the time.

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.

Main Takeaway

  • 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