Holosun 509T in detail

Holosun 509T is a compact sized red dot from Holosun. In this article we cover details of this red dot. It is not review as such, instead we put all valuable information into this post so that you can decide yourself whether this optic device will work for you or not.

Mounting compatibility

Compatibility of red dots is solve by a footprint.

What does footprint stand for? Well as any other footprint, in this case also footprint tells us what does the bottom of the red dot look like.

With that information we will understand what kind of mounting device we have to use in order to fit the red dot. I.e. what is the positoin of the pins and screw holes of the red dot so that we can mount it.

Why is it important? It is one thing to get the best red dot, but it can be another thing to be able to mount the red dot to the gun you want. Luckily, most of the manufacturers share 4 or 5 main types of footprints to accomodate its red dots.

Holosun 509T footprint

Holosun 509T X2 has different footprint from other red dots incl. other Holosun red dots. Given the footprint is unique only for Holosun 509T, its not considered a footprint standard. You will simply need to search for red dot mount or red dot plate made specifically for Holosun 509T.

Holosun 509T footprint consists of a central block 15mm wide which then extends to a thinner block of 5mm that goes to 2/3 of the width of the red dot.


Holosun 509T is compact to subcompact sized red dot. The dimensions of this optic device correspond +- to the Holosun EPS and Holosun EPS Carry red dots. They however share different footprint, and also the height of the red dot is slightly higher for Holosun 509T.

Compared to EPS Carry & EPS the 509T model is much heahvier: by 0.72 oz compared to EPS Carry and by 0.32 oz compared to EPS. Holosun 509T weights 1.72 oz.

The higher weight is caused by the large titanium body. For example Holosun SCS MOS which is also made of titanium, but has thinner body, weights 0.42 oz less. On the other hand, the long gun red dot Holosun 510C with titanium hood weights almost 5 oz.

The dimensions of the red dot are following:

Length: 41mm / 1.6 in
Width: 29mm / 1.16 in
Height: 29mm / 1.13 in
Weight: 49g / 1.72 oz

The dimensions of the red dot window are slightly larger compared to both EPS and EPS Carry. That is given the overall higher body of the red dot. The dimensions are following:

Width: 23mm / 0.9 in
Height: 17mm / 0.66 in


You can download the Holosun 509T X2 guide.

Frequently asked questions

You may be looking for answers to one of these questions. For each find the answer below.

What footprint is the Holosun 509T?

Holosun 509T uses unique footprint that does not fit any of the other footprint standards. Mounting device has to be made specifically for Holosun 509T.

How to turn on Holosun 509T?

Press and release either the “+” or “-” button in order to turn the red dot on.

How to turn off Holosun 509T?

Press the “+” and “-” button at the same time in order to turn the red dot off.

How to change reticle on Holosun 509T?

Press and hold the “-” button for 3 seconds in order to change the reticle.

How to adjust Holosun 509T?

To adjust height you have to use the elevation screw on top of the tail of the red dot.

To adjust side you have to use the windage screw on the right side of the housing of the red dot.

How to change battery in Holosun 509T?

Unscrew the screw on the right side of the red dot that holds the battery cover.

Subsequently remove the cover to approach the battery of the red dot.

The battery is CR1632.

Technical data

Reticle 2 MOA Dot & 32 MOA Circle
Light Wavelength 650nm
Reticle Color Red
Parallax Free Yes
Unlimited Eye Relief Yes
Magnification 1x
Multi-Coatings Yes
Power Source Solar & Battery
Battery Type CR1632
Battery Life (Hours) 50000
Brightness Setting 10 DL&2 NV
Window Size 0.66×0.9
Dimension (in) 1.6×1.16×1.13
Weight (oz) 1.72
Housing Material Titanium
Surface Finish Titanium
Adjustment per Click 1 MOA
W&E Travel Range ±30 MOA
Storage Temperature -40℃~70℃
Working Temperature -30℃~60℃
Submersion IP67
Vibration 5000G


Leave a Comment