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Holosun HS403G Red Dot unboxing and first impressions

If you'd rather watch the full unboxing and walkthrough, you can watch the video here:


In this post, I’m doing a quick unboxing and first look at the Holosun HS403G, which I picked up for my 300 Blackout build. I just finished putting the rifle together and wanted to go over what comes in the box, how the optic works, and my initial impressions.

This is the HS403G model, which comes in some of the nicer packaging I’ve seen from an optic in this price range — a solid plastic case instead of cheap cardboard.

What Comes in the Box

Inside the case you get:

The Holosun HS403G red dot

Rubber lens covers

Instruction manual

CR2032 battery

Torque limiter tool for mounting

A low mount

A high mount

I specifically chose the model with the external battery tray. There is a version where the battery mounts underneath the optic, but that requires removing the optic from the rail. Even though the battery life is very long, I didn’t want to deal with that hassle.

The external battery does make the optic sit slightly higher, but I don’t think it’s a big deal at all.

Optic Features and Controls

The lens looks great. The window is on the smaller side, but it’s not bad and feels perfectly usable.

Brightness adjustment is done using the plus and minus buttons. At the highest setting, the dot is very bright, and it can be turned down to a very faint level for low-light use.

One of the main reasons I picked this optic is the auto wake / sleep feature.

Auto Wake and Sleep Mode

The HS403G has a motion-activated system that puts the optic into sleep mode when it’s not moving, then turns it back on automatically when motion is detected.

You can:

Turn the feature off

Or set the sleep delay up to 12 hours

I personally set mine to 1 hour, since I don’t need the dot staying on longer than that when the rifle isn’t being moved.

To adjust the sleep timer:

Hold the button for about three seconds

The dot will blink to indicate the current setting

Each press increases or decreases the delay

Press both buttons together to confirm

It works exactly as advertised — once it goes to sleep, any movement instantly turns it back on.

Adjustments and Build Quality

The adjustment turrets are nicely done:

Larger caps that are easy to handle, even with gloves

Very positive, audible clicks

Adjustment directions are printed inside the cap, which is a really nice touch

One thing worth pointing out is that the front lens is slightly angled. Some people think this means the optic is crooked or defective — it’s not. That angle is intentional and normal for red dots like this.

Specs and Final Thoughts

A few highlights from the manual:

Rated for 50,000 hours of battery life

Waterproof (IP67)

Remembers last brightness setting

Motion sensor always enabled when powered on

Lifetime limited warranty for the original purchaser

The optic is made in China, and I’ve heard it may come from the same factory as some Primary Arms red dots, though I haven’t confirmed that myself.

So far, it feels very solid and well-built. I’ll be taking it out soon to see how it holds up in real use, but first impressions are very positive.

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