Many years back, fixed power optics were very common. They tended to be larger in size when compared to say, a standard tube style red dot. Fixed power optics have come back around thanks to the small magnified prism optics like the Primary Arms SLx 3x MicroPrism. The SLx is so much lighter and smaller than the fixed power scopes of the old days. The SLx 3 power prism also gives you plenty of new benefits that just weren’t available back in the day. So let’s welcome in the small, fixed 3 power optic of the future. Now offered in FDE to match all your tactical needs.

Primary Arms set the bar high when they released the 1x MicroPrism, then they raised it with 3x and 5x models. They sent me out the 3x version in FDE. Fixed power optics have their place in the shooting world. With the SLx 3x you get a super small package size plus some magnification to see targets at mid range distances. Since the magnification isn't super overpowering, you can still use this optic up close. It also doesn’t weigh much, tipping the scales at just about 8 ounces. For being in Primary Arms’ SLx line of products, you get an exceptional value with super clear glass.

One of the great aspects of the Primary Arms 3x MicroPrism is its reticle. Primary Arms uses one of their ACSS reticles, or “Advanced Combined Sighting System”, in the SLx 3x. In particular, this is the Raptor ACSS reticle. The ACSS Raptor gives you ranging, bullet drop compensation, wind holds, and moving target leads, all in a simple to use red colored reticle. The reticle has an illuminated horseshoe around a center chevron (think triangle instead of dot). The ranging, wind and bullet drop then take up the reticle below the center chevron, these compensations are not illuminated. The illuminated section has 13 intensity settings, 3 of which can be used with night vision. Using the ACSS Raptor is really easy. The large horseshoe lets you shoot up close targets quickly, even though the SLx is a 3 power optic. The chevron and stadia then give you precision shots out farther. I found the reticle to be a good compromise between close and far range targets. Being a 3 power prism sight, I am a little slower at shooting an array of close in targets, but I am more accurate when out at farther distances. Primary Arms did a good job with the reticle on the SLx 3x MicroPrism. The illuminated part of the reticle is “daylight” bright, even in direct sunlight. If, for some reason, it does wash out a tiny bit, the reticle is etched into the glass, so you get your typical non illuminated black reticle anytime, even if the battery goes dead.

If you are worried that the SLx 3x MicroPrism won’t work for your firearm, don’t fret. Primary Arms gave the MicroPrism plenty of mounting options, and they all come with the optic. The SLx manual states 8 different mounting heights. This is from essentially rail height (1.1” to center of prism) to 2.075” to center of optic. There is also one other option. If you have a carry handle AR, fixed or removable, the SLx MicroPrism will mount directly to the carry handle. If you want to use a different mount than the ones supplied, The SLx MicroPrisms use an industry standard “Mini Prism” footprint.

One aspect of the Primary Arms MicroPrisms is their exceptional clarity. For the price you pay for one of these, you get extraordinary clear glass. I’ve also found that even though the eye relief is stated at 2.7”, it is very forgiving. Since the MicroPrisms have an etched reticle, they also don’t have the clarity problems for people with astigmatisms. Making the ACSS reticle super clear. Being that this SLx MicroPrism is 3 power, it also has a decent field of view at 100 yds, which is 38 ft. So you will see a 38 foot wide circle, when looking through the prism sight, at 100 yards.

The SLx 3x MicroPrism also has a few other features that need mentioning. First off, it uses Primary Arms’ “AutoLive” motion sensing on and off. So when you pick up the SLx prism, the reticle turns on at whatever brightness the knob is set to. After not sensing any movement for a few minutes, the optic goes back into a hibernate mode, where the reticle is off. Once you move the optic, the on cycle starts again. I absolutely love the AutoLive technology and it works fantastic on the Primary Arms’ MicroPrisms. This AutoLive also gives the 3x MicroPrism a battery life of around 29,000 hours. Which is fantastic for any magnified optic. The windage and elevation adjustments are also protected from being hit or accidentally turned. You can even adjust them using the rim of a cartridge. I’ve done it, it’s easier than looking through the range bag for a tool.

The Primary Arms SLx 3x MicroPrism fits in well for a fixed mid range optic. It allows close range work too. Everytime I look through one of the Primary Arms MicroPrisms, I am surprised by the optic clarity. Add in the AutoLive function and you have a great combo of features. So if you are looking for a small fixed 3 power optic, check out Primary Arms’ line of SLx MicroPrisms.

Firearms Insider Reviews - 8 Key Points

Claim to Fame:

Small, lightweight fixed 3 power prism scope

Target Market:

Those wanting a small profile, fixed 3x sight

FNBs (Features & Benefits of this product):

FDE finish
13 total illumination settings, 3 are NightVision compatible
Daylight Bright
AutoLive motion-sensing on/off battery saving technology
Length: 2.95”
Weight: 7.95 oz.
Illuminated and etched ACSS bullet drop reticle
Field of View: 38.0 ft @ 100 yds
80 MOA Adjustment
0.25 MOA Click Value
8 Mounting Height Options
One CR2032 Battery (Included)
Up to 29,000 Hours on medium setting
Industry Standard Mini Prism Mount Footprint
Eye Relief: 2.7"
Lens Covers
Lifetime Warranty

What other aesthetic options or finishes are available?

Black anodized, Griffin MIL reticle

What others are saying?:

5 out 5 stars - Devin at PrimaryArms.com

WOW, PRIMARY ARMS REALLY GOT IT RIGHT WITH THIS ONE!

This is Primary Arms Optic number 3 for me, but will definitely not be the last!

I got this optic for a lighter weight, simplified build. Got tired of dealing with heavy rifles and playing around with LPVO's, so this became the obvious choice. I was a bit skeptical about the fixed 3x magnification, but after zeroing it this afternoon I didn't have any issues taking shots at 100 and 150 yards, ran out of daylight to try any longer distances. However, I don't think I'll have any issues making hits out to 300–400 yards.

I know this is a "budget" priced optic, but I'm pretty impressed, the glass is really clear. The reticle is sharp and informative without being cluttered like so many optics are. Oh, and speaking of the reticle, the illumination is very bright on the maximum setting, much brighter than my LPVO and gen 1 Cyclops prism. I would say it's daylight bright, I actually ended up dropping it down to the 9th or the 10th setting to use during the day.