Almost two years ago I reviewed Primary Arm’s SLx 1x MicroPrism. Since then they have made magnified versions. Well, they are coming out with an SLx 5x MicroPrism and I requested one for review. New for the 5X MicroPrism is their 12 o’clock red dot mount so I requested one of those as well. Let’s take a closer look at this tiny but mighty setup.

Primary Arms @ TFB:

• Three NEW Optics From Primary Arms: Two Rifle Scopes And A Red Dot
• Primary Arms Mini Reflex 12 O’clock Mount for PAO MicroPrisms
• [NRAAM 2023] LOUD NOISES! Primary Arms Range Day 2023

SLx 5X MicroPrism

I will be honest, other than taking this picture, I did not use the SLx 5X MicroPrism like this. I immediately removed the optic from the mount and installed Primary Arms’ 12 o’clock red dot mount.

With regards to the SLx 5X optic, it is very similar in size to the SLx 1X. It is a little bit longer but not that much more. If you recall, the SLx 1X windage and elevation adjustments were 1 MOA. Well the SLx 5X is just like their 3X, it has 0.25 MOA adjustments.

The SLx 5X with a 12 o’clock mounted red dot weighs 2/3 of what a Browe BCO and the BCO is only 4x. ACOGs weigh 15.1 oz with mount but those are also only 4x magnification.

I had originally requested the MIL reticle version of the SLx 5X. See the reticle sample below.

They ended up sending me the 5.56/.308 reticle instead.

I am happy they did. After requesting the MIL reticle version I thought about how I would review this optic. The MIL reticle is nice but that is more suited for precision rifle or spotting scopes. I just do not see myself using those windage holds that much for a 5x optic.

Here is the explanation of the BDC reticle from the SLx 5X manual.

PAO 12 o’clock RDS Mount

Apparently, Primary Arms customers have been asking for a red dot mount for the SLx MicroPrism. Well, the 1X is too short but the 5X has enough room and magnification that a piggyback red dot makes sense. This piggyback mount is made of 6061 aluminum and retails for only $29.99. It is only $24.99 if you bundle it with the SLx 5X scope.

To make the 12 o’clock mount universal, Primary Arms cleverly decided to use the GLOCK MOS pattern. So you just need an adapter plate to mount your optic of choice.

I do not have any GLOCKs with MOS so I borrowed a spare plate from my neighbor Benny.

Just to test it out, I mounted a spare Crimson Trace CTS-1250 onto the plate. One issue I noticed is if the screws for the optic are too long, it will push the MOS plate away from the mount.

So I changed my plans and bought a Holosun SCS MOS green dot instead. Now it direct mounts to the Primary Arms 12 o’clock red dot mount.

SLx 5X Is Night Vision Compatible

You should know by now that I will test things with night vision. While Primary Arms claims the SLx 5X is compatible with night vision, I do not find aiming passively through magnified optics while wearing helmet-mounted night vision to be ideal. The eye relief on the SLx 5X is decent but trying to fit a PVS-14 or dual tube goggles behind it is not great. You would have to increase LOP on your stock hoping there is enough room to get behind the MicroPrism with your NVGs. Instead a clip-on is more apt and I found the size of the SLx 5X to be perfect when trying to mount clip-on night vision onto short guns with short top rails.

One gun in particular that is difficult to mount clip-on night vision is the Pork Sword. The top rail is not that long so either I have an optic or I have night vision, but not both. The SLx 5X is small enough that I can fit it and a PVS-30 onto the top rail.

Just to see how it feels, I put it on my 6.8 SPC AR pistol.

After lowering the SLx 5X to its lowest mounting option, I found a home for it on my Springfield Hellion. There is even enough room for my PVS-27. If I did not have the 12 o’clock reflex sight mount, I could have the PVS-27 even further back.

Here is what the SLx 5X looks like when a clip-on night vision device is mounted in front of it. The shed is 530 yards away.

Here is a torso-sized steel target 475 yards away.

Shooting The SLx 5X MicroPrism

Once I mounted the SLx 5X MicroPrism onto my Springfield Hellion, I decided this is where it will stay. The height is perfect for a comfortable cheek weld and eye relief is decent.

The height over bore for the 12 o’clock dot is significant but it is only for shooting close range within 25 yards. As per the manual below, I zeroed the SLx 5X at 100 yards.

This is a steel target 100 yards away.

It was difficult getting a photo through the SLx 5X but here is my sight picture at the 475-yard steel target.

The BDC worked pretty well out to 475 yards. I tried an 800-yard target but the rounds were hitting low. It was easy enough to adjust the elevation for it but shooting 55 gr out of a 16″ bbl that far is not something I plan on doing a whole lot. I have other rifles and calibers for shooting that far.

Final Thoughts On the SLx 5X MicroPrism

I really like the form factor and functionality of the SLx 5X MicroPrism. It is tiny and yet has a decent magnification level for use at medium-range distances. I always found 3X to be too low magnification and while ACOGs are a gold standard, I just haven’t found them to my liking.

The Primary Arms SLx 5X MicroPrism retails for just $399.99 and is available now. If you opt for the reflex sight mounts it is just an additional $24.99. Like the other SLx MicroPrisms, you can mount this to an AR15 carry handle, just not the 12 o’clock reflex sight mount.   For more information check out the SLx 5X MicroPrism on Primary Arms’ website.

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