Optic of the Week: AN/PSQ-18A M203 Day/Night Sight


I really really wanted to like this but it just sucked so bad.

I mean, it provides a capability that nothing else does, but it is so awkward to use I’d rather live with out it.

Part of the problem with equipment like the AN/PSQ-18A is that when you see one for sale, it is often stolen military property. If you see one with the serial number removed, it probably fell of the truck. Now there are legit units out there, but you still are not likely to get any service from Insight should anything break. A short while back I found a unit for sale that I felt comfortable buying.

The sight comes with a case, manual, and detachable accessory rail.

The AN/PSQ-18A is a day/night sight for the M203 grenade launcher. The night sight being the important aspect as there are very few sights for the M203 that work in darkness.

PSQ-18A mounted on a M4, an Aimpoint Comp M4 mounted on the accessory rail.

This sight slides onto and clamps to the barrel of the M203. This might make it one of the most consistent sights for the M203 as there is a great deal of slop and movement between the barrel and the action on one.

This sight is adjustable from 0-400m in 5 meter increments. It has flip up iron sights with tritium inserts for use at night, and it has an IR laser for aiming with night vision. You can take the accessory rail and mount it on the top of the side of the unit to attach an additional visible laser or day optic.

This optic will let you, in total darkness, aim and fire your M203 out to 400m in 5m increments. That is something special.

But, it is large, heavy, awkward, and a pain in the ass to use.

With out batteries, you can still use the optic day or night with the iron sights. The rear sight has two positions, each with an odd design.

One position of the rear sight is a post with a tiny little notch in it. Far too tiny to put the whole front sight in it. The other is a circle with tabs letting you center the front sight and align it vertically with the tabs.

There is a knob on the front bottom of the unit to adjust the range. If the unit is off or unpowered, there is a scale on the side next to the M203 so you can manually see the range.

Yeah, I can’t read it either.

When you power it on, then is when the cool features become available.

It takes a single AA battery that installs in the front bottom.

Then you can use the selector to turn it on and select which features you want to use.

Note there is a lockout for high power, so you can disable high power when training.

When turned to day mode, there is an LCD at the back that shows what range the unit is set at. The LCD will flash if the firearm is canted. There is also a green light near the front of the unit that blinks to show if it is canted.

A 25mb video becomes a 125mb gif. I cropped it to 31mb just so you wouldn’t have to hit play on a video.

Note how both the green light and the black bar on the LED screen flash when the M203 is canted. If you are using the IR aiming laser, the laser will flash while the unit is canted.

On the right side of the barrel, in the perfect position to hit with a thumb if you are left handed, or your support hand trigger finger if you are right handed is a button to activate the IR laser.

There is a version of this device made for the M320 launcher. It is similar but instead of clamping to the barrel it attaches to a side rail (left side of a weapon). I am told that to use the IR laser on that model you much use a tape switch.

So, this thing seems awesome. The ability to precisely aim your indirect fire weapon day or night with passive or active aiming, what is there not to like.

First, it is bulky, really bulky.

Then, because it is mounted to the barrel, it is really low on the weapon. While you can use it for 0-300m, I was not able to shoulder my weapon and find a way to look though the irons, or an attached optic in any sort of reasonable fashion. Ergonomics were terrible. Now once it was set between 300-400m. That it when I was finally able to use it well. To be fair, that is also past the range the most commonly used sight, the leaf sight, goes out too.

When I took this out to the range to use it, I was going to fire a couple rounds at 50m for fun and to get the feel of it. I could not aim down the sights on the PSQ at 50m. I realized this just was not going to work for me. I feel this sight is only really useful at night or in the 300-400m distance.

My biggest complaint is the adjustment. Having to turn a dial is slow. Going from 100m to 350m zero setting is slow. Even worse, it doesn’t always acknowledge that you made a click. I could make a click adjustment unit would not recognize the adjustment.

I tried to show the issue in this video. Sometimes when I make a single click, it would not recognize the adjustment. Or sometimes when I might make multiple clicks, it would show an adjustment less than what was done.

Now if you are using a M203 at night, with night vision, this would be an excellent tool. But past that, it was just so awkward to use I didn’t even bother trying to shoot with it. I went ahead and sold it off.


  1. I can definitely see it being useful for people/groups that do the majority of their work at night but outside of that yeah that’s pretty clunky. Still a super cool write up though. didn’t even know such a thing existed.


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