Hands-On: Primary Arms 1-8 Acss Review

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Are you on the lookout for a general purpose, jack-of-all-trades optic for your AR-15 carbine or other medium-range rifle platform? Do you need high quality performance at a price point that won't break the bank? If so, the Primary Arms 1-8x ACSS may just be the ideal optic for your needs.

Full disclosure: I'm a big fan of Primary Arms' products. Their micro red dot was the first optic I ever put on my AR, and I've been impressed with their performance, durability, and features ever since. But I'm not going to let that get in the way of giving you an honest opinion on this scope – no optic is perfect, and no matter how much I might like a manufacturer, I'm still going to call out poor design choices, flimsy materials, or any other issues I might come across.

With that out of the way, let's take a closer look at what we're dealing with.


primary arms 1-8 review

The SLx 1-8x24mm ACSS is a straightforward upgrade of Primary Arms' older 1-6x optic, offering additional magnification in a scope body that is actually slightly shorter in length and lighter in weight. This optic is what is known as a low-power variable optic, or LPVO. These optics have exploded in popularity in recent years, and for good reason: they offer an amazing amount of versatility, capable of accurate fire throughout the entire effective range of many popular rifle platforms such as the AR-15 and AR-10.

Primary Arms has designed this optic as a relatively budget-friendly piece of gear, but don't let the price tag fool you: the build quality and overall performance is excellent, and while it might be outclassed by expensive, top-of-the-line optics such as the Trijicon ACOG, Leupold MK5 HD, or the Swarovski Z8i, it more than holds its own against other options in its price range.

With a 10-inch total length and a 16.9 oz weight, the 1-8x ACSS is quite a bit more compact than most of the other LPVOs it's competing with – especially compared to other 1-8x scopes.

But what sets this optic apart from the pack more than any other feature is its ACSS reticle, which just might be my favorite multi-purpose reticle on the market today. We're going to get into that in more detail down below, but first, let's see what you're getting for your money.

Primary Arms SLx 1-8 Acss

The price of Primary Arms 1-8 Acss varies, so check the latest price at

What's in the Box?

If you're buying this optic brand new, you can expect to open the box and find:

  • The optic itself, with a battery installed
  • An instruction manual
  • A cleaning cloth
  • A spare CR2023 lithium battery stored under the windage adjustment knob capEnter 

Nothing too fancy, though the spare battery is always welcome. The instruction manual is actually pretty useful, as not only does it go into a very detailed breakdown of the reticle, it also offers some information on zeroing in the optic based on the caliber you're shooting (the version we're testing is designed for use with .223 / 5.56, 5.45x39, or .308 ammo).

The only thing you'll need to pick up to start shooting with this optic right out of the box is a scope mount – I'd personally recommend a cantilever option like the Primary Arms GLx 30mm, especially since the eye relief is fairly forgiving.

The scope also comes with some plastic flip-up caps installed – they feel fairly flimsy and I don't expect them to last all that long, but I prefer to remove them anyway. If you prefer using lens caps, it might be worth picking up a slightly sturdier pair of those as well.

Primary Arms SLx 1-8 Acss

The price of Primary Arms 1-8 Acss varies, so check the latest price at



Overall, I walked away pretty impressed by this optic's quality and performance. The glass is clear and sharp, though obviously not at the same level as what you'll find in a $1000-2000 scope. At 1x magnification, there's a very slightly amount of edge distortion, but it's really only noticeable at extreme close ranges – if you're using it for both-eyes-open shooting at CQB ranges the same way you'd use a red dot, you aren't likely to notice it at all.

It's also worth pointing out that it's not quite a “true” 1x magnification – it looks closer to 1.2x to me, and while the field of view is excellent for a 1-8x scope, a good red dot or holo sight will be still slightly faster to acquire targets inside of 25 yards or so.

primary arms 1-8 acss

Sharpness and clarity are excellent throughout the entire magnification range, and thanks to the 30mm main tube, light transmission is quite good.

The ACSS, or Advanced Combined Sighting System, reticle is the main selling point for this optic, and it's definitely one of my favorites. It uses a large outer horseshoe reticle with a more precise chevron in the center that will look familiar to anyone who's spent any time behind an ACOG, and I personally prefer this design over a standard dot as it doesn't cover up your target at longer distances while still allowing you to use the horseshoe for extremely fast target acquisition in close quarters.

The reticle has bullet drop compensation (BDC) hashmarks out to 800 yards, as well as holdovers for windage and for moving targets (both walking and running). It also includes both vertical and horizontal auto-ranging markings, allowing you to quickly and accurately estimate the distance of an average man-sized target out to 800 yards. If this all sounds overly complicated, don't worry – it's a lot of information, but the sight picture isn't cluttered, and once you take it for a spin you'll realize how intuitive it actually is.

primary arms 1 8x

If you can't tell by now, this is definitely designed as a combat optic, but those same features also make it quite attractive for hunting use. Being able to quickly dial in the range of a coyote, then adjust for its movement, the wind speed, and distance, then make an accurate shot all without having to do any complex calculations or spin any knobs around is a great feeling.

The illumination knob has 11 brightness settings (none of which are night vision compatible, unfortunately), and while it's not as bright as some of its competitors, you still get more than enough illumination to use it on a sunny day, and I didn't notice any of the washed out, red “halo” effect you sometimes see in budget-priced optics.

The reticle is etched, which means it will still be perfectly functional even if the battery runs out, and in all honesty I actually prefer to run it with the illumination turned off except in low light conditions. The reticle is thick, dark, and sharp enough to be easily visible even against deep brush or heavy tree cover, and I can't imagine having any trouble picking it out unless I was aiming almost directly into the sun on a very bright day.

primary arms 1-8 acss review

Do note that this is a second focal plane scope, which means the reticle stays the same size throughout the entire magnification range, and that the holdover markings are only accurate when the scope is set to its maximum magnification level. It's highly unlikely that you'd be using anything lower than the 8x setting if you're worried about adjusting for windage and elevation hundreds of yards out, but I did want to mention it as some people simply do not like SFP riflescopes.

The ½ MOA windage and elevation adjustment knobs are smooth, and I was able to hear and feel them click. The adjustments are accurate, though you shouldn't expect tracking to be on par with a high-end target-shooting scope. But the main advantage of this optic and its reticle are that you don't need to spend time fiddling with knobs – zero it in at 100 yards, and you're able to use the holdover markings for everything else.

Finally, in terms of durability, the Primary Arms SLx 1-8x ACSS feels very sturdy. The main tube is built from a single piece of aircraft-grade aluminum and is nitrogen-purged, which means it's waterproof, shockproof, and fog proof, and while the matte black finish will start to wear if you're rough on your rifles, the optic will keep on ticking just fine. The lenses are also fully multi-coated to reduce glare and reflections, as well as to keep dust and grit from scratching up your glass.

If nothing else, Primary Arms has a very reasonable warranty and excellent customer service – I've never had one of their optics fail on me, but I am totally confident that they'd take care of the problem without any fuss if I ever did need to call on them.

Pros / Cons


  • The ACSS reticle is excellent and intuitive to use
  • Lighter and more compact than most other comparable LPVOs
  • Extremely versatile magnification range for most applications 


  • Not a true 1x magnification setting
  • Illuminated reticle is not as bright as some competitors


So what other optics deliver the same basic features, functions, and performance at a comparable price point? There's one obvious answer, and it's an optic produced by another of my favorite manufacturers:





Vortex Optics Strike Eagle 1-8x24mm Riflescope

Vortex Optics Strike Eagle 1-8x24mm Riflescope

  • Diameter: 24mm
  • Magnification: 1-8x
  • Length: 14.9 in

Primary Arms PLx 1-8x24mm FFP Scope

Primary Arms PLx 1-8x24mm FFP Scope

  • Diameter: 24mm
  • Magnification: 1-8x
  • Length: 11.02 in

1. Vortex Optics Strike Eagle 1-8x24mm Riflescope

Vortex Optics Strike Eagle 1-8x24mm Riflescope

The Strike Eagle 1-8x24mm is a direct competitor to the Primary Arms SLx 1-8x24mm, and if you put them side by side you might even say the resemblance is a little suspicious. Both of them are near-identical in terms of features and functionality, offering the same magnification range, the same degree of illumination, similar reticles, and even similar design profiles.

While I do prefer the ACSS reticle and found the clarity of Primary Arms' glass to be slightly superior, the Vortex Strike Eagle's reticle is also very intuitive and easy to use, and is arguably slightly less busy. 

The other thing I really appreciate about the Strike Eagle is the inclusion of a throw lever that allows the shooter to move through the magnification range more rapidly, which is a much appreciated feature for hunting and competition shooting.

Finally, Vortex's VIP Warranty is one of the best in the industry, and if you're extremely harsh on your gear, that's something to keep in mind. Both optics are offered at almost the same exact price, and both are top-tier options for budget-conscious optics that are still rugged and reliable enough to use for home defense, hunting, and competitive use.

Or, if you have a significantly bigger budget allowance for your optic and want an upgraded version of the SLx 1-8x optic, Primary Arms also offers its extremely high-end “Platinum” version of the optic:

Vortex Optics Strike Eagle 1-6x24mm

Vortex Optics Strike Eagle 1-8x24mm

The price of Vortex Optics Strike Eagle 1-8x24mm varies, so check the latest price at

Want to know more about that scope? Check out our detailed Vortex Strike Eagle 1-8×24 review.

2. Primary Arms PLx 1-8x24mm FFP Scope

Primary Arms PLx 1-8x24mm FFP Scope

If you're a fan of the ACSS reticle and the overall form and function of the PA SLx 1-8x but refuse to compromise in any aspect of your optics' quality, the PLx version of the same scope will be right up your alley. The Japanese glass is incredibly clear, on par with some of the best scopes available at any price, and the main tube is further strengthened with an anodized hardcoat.

Unlike it's more budget-conscious cousin, the PLx is a first focal plane scope, which means the holdovers remain true at all magnification levels instead of requiring you to max out the magnification to use them accurately. 

This mostly comes down to user preference, and since you're not likely to be using the elevation and wind holds at anything other than max magnification in the first place, it's rarely going to be a dealbreaker, but some people have very strong opinions on the subject.

The adjustment knobs on this model also get an upgrade, switching to more precise .1 MIL adjustments with locking turrets and zero reset. All in all, the PLx is a step above in almost every aspect of build quality, but the price tag very much reflects that. It's probably overkill for the vast majority of shooters, but if you're a professional competitive shooter or in a position to choose optics for tactical use such as in SWAT or other law enforcement applications, it's certainly something to consider.

Primary Arms PLx 1-8x24mm FFP Scope

The price of Primary Arms PLx 1-8x24mm FFP Scope varies, so check the latest price at

Final Verdict

For less than $400 on Amazon or OpticsPlanet, the Primary Arms SLx 1-8x scope is a very hard optic to beat. If I haven't mentioned it enough already, I'll reiterate that I think the ACSS is one of the best reticles available, period – for both tactical and hunting purposes, it offers enough information to quickly and easily make accurate shots from 0-800 yards, even on a windy day and against a moving target.

LPVOs like this one are an excellent all-purpose option for shooters who want to be able to engage targets at any range, and while I'd say the sweet spot is probably in the 50-300 yard range, it is still an excellent CQB optic and still more than capable of ringing steel targets out at 800 yards as well.

True, it may not outperform a red dot at extremely close range, or drive tacks like a high-power scope designed for long range target shooting, but installing this versatile optic on your rifle means you'll be able to hold your own in any situation you may find yourself in.

As both a 3-gun shooter and a hunter, this optic suits my needs very well. Acquiring targets at different ranges is a smooth and fluid process, and once you've put a a few dozen rounds downrange and gotten a feel for the reticle, making on-the-fly aiming adjustments feels like second nature. I can also say I've never had reliability issues with a Primary Arms optic, and I'd have no qualms about using this one on a dedicated home defense rifle, either.

Any way you slice it, this is a great scope and an excellent value for the price.

You can also check Hunting Mark's Best Home Defense Rifle.

Parting Shots

Choosing the right optic for your rifle can be a daunting task, especially when you factor in the flood of cheap knock-offs and substandard materials that tend to crop up when you're looking for “budget” scopes. Luckily we've taken the time to sift through all of the junk and bring you a detailed look at the optics that meet our exacting quality standards.

We've put quite a few optics through their paces here at Hunting Mark, and our goal is always to provide a complete, no-BS perspective on the equipment we review. That's why I'm happy to say that the Primary Arms SLx 1-8x24mm riflescope is an impressive option that ranks among my absolute favorite sub-$500 optics, and I'd readily recommend it to recreational shooters, hunters, or entry-level competitive shooters without any hesitation.

Have you tried this scope, or any other similar products that you think we should know about? Sound off in the comments below! We love hearing from readers—especially if we help you pick out the perfect new piece of gear. And if you want to check out our impression of the similar 1-6x version of this optic, head on over to our review of the Primary Arms 1-6x scope


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