Primary Arms 2.5X Compact AR15 Scope Review

The Primary Arms 2.5X Compact AR15 Scope has a reputation for being popular, versatile, and lightweight. And if you’ve recently bought a new rifle and are looking for an affordable scope, this is highly recommended by firearms aficionados.

But does this Primary Arms model live up to its reputation? Does it give you more bang for your buck as advertised?

Let’s delve deeper into this scope to find out its top features, its general specifications, and its pros and cons in my in-depth Primary Arms 2.5X Compact AR15 Scope Review.

primary arms 2 5x compact ar15 scope review

Who are Primary Arms?

Primary Arms is a market-leading firearms and accessories manufacturer and retailer. They are based in Houston, Texas, and have a reputation for providing high-quality optics for affordable prices. First established in 2007, Primary Arms has grown exponentially over the past decade and currently exports to 17 countries, including Canada, the UK, and New Zealand.

They are largely known for producing scopes that feature their own patented ACSS reticle system. Their entire business ethos was built on the concept of providing high-quality products to gun enthusiasts, professional shooters, hunters, and law enforcement and military personnel.

Primary Arms is one of the most recognizable names in the American firearms industry. They are widely known for their affordable products and a customer service team that knows their stuff.


You don’t usually find scopes with these high-level specs in this price range. This Primary Arms Compact Scope comes with a magnification of 2.5X, perfect for accurate and precise mid-range shooting just beyond red dot distances. And it’s even more accurate at closer distances.

It utilizes the Primary Arms’ patented CQB ACSS Reticle that offers 12 different brightness settings that help you to match your aiming point in all weather conditions. The fully illuminated reticle allows you to easily hit targets at 600 yards, although 200 to 250 feet is the ideal range.

This scope has 2.67” of eye relief, a Field of View of 37.5ft at 100 yards, and is also a 1/2 MOA at 100 yards. The reticle will also aid crisp and clear imaging and impressive ballistic drop compensation. It is lightweight, portable, waterproof, and fog-proof, making it the ideal scope for any hunting trip.

What’s in The Box?

Before we take a closer look at the scope’s top features, let’s find out what you get for your money…

  • Primary Arms 2.5X Scope with patented reticle.
  • Lens cover.
  • Lens cloth.
  • Flip cap.
  • CR2032 Battery.
  • Picatinny Mount.
  • Installation hardware.

PAC AR15 Scope Top Features

One of the most refreshing things about this scope is its simplicity. This is very easy to use and doesn’t have all the bells and whistles you find on high-end scopes. But it makes up for that with its durability and practicality. So, let’s take an in-depth look at the top features of this Primary Arms scope.

  • ACSS CQB-M Patented Reticle.
  • Shockproof, waterproof, and fog-resistant.
  • 12 brightness settings.
  • Removable Picatinny mount for AR15/M16 carry handles.
  • Compatible with industry-standard ACOG mounts.

ACSS CQB-M Patented Reticle

The cornerstone of this product is the patented ACSS reticle. And it really is the star of the show. ACSS stands from ‘Advanced Combined Sighting System’ and makes the imaging very crisp and clear.

The reticle is etched in the glass, which means its visible without any illumination. It’s also designed to specifically handle each type of caliber and magnification. This feature is ideally suited to flat-trajectory rounds like the 5.56 and 5.45×39. It’s also suited to the 7.62×39’s smaller and higher velocity brother. The scope can also handle some high velocity .308 rounds.

primary arms 2 5x compact ar15 scope guide

The reticle works well against natural backgrounds as the clear glass helps to show the fine details on trees and other foliage. In most cases, you won’t need to turn on the illumination to increase the contrast. But when you do illuminate the reticle, the images stay ultra-crisp, which is perfect for shooters with astigmatism.

12 Brightness Settings

The reticle comes equipped with 12 brightness settings that allow you to configure the scope to the environment’s light levels. This fully illuminated design feature ensures you will get clear imaging at any time of the day or night and in all weather conditions. It also features a ‘daylight bright’ mode which is ideal for use in conditions where light is fading fast.

Removable Picatinny Mount

The flexible 1913 MIL-STD Picatinny thumbscrew mount can be easily removed and replaced with any mount that is compatible with AR15 carry-handle optics.

Build and Specs

Primary Arms’ scopes are often revered for their sturdiness and being built like a tank. In fact, this is one of the toughest and most rugged scopes on the market. The aluminum construction is durable and reliable, and a great choice on hunting trips in hazardous weather conditions.

The type-II hard-coat anodized matte black finish provides the utmost protection to make this scope shockproof, waterproof, and fog-resistant. This scope is virtually indestructible and will last the test of time.

The controls don’t feature many buttons and are quite easy to use. It’s quite simple to adjust the illumination knob to control the brightness settings. You can also easily remove and replace the CR2032 battery just by turning the cap counterclockwise.

primary arms 2 5x compact ar15 scope

You will find the elevation adjustment just in front of the illumination adjustment that can quickly shift the point of impact up with the scope. And to the right of the scope, you will find the ‘windage’ option that can be adjusted to alter the point of impact with your visuals.

The scope’s weight is 14.9 ounces, which is relatively light and easy to transport on hunting trips. In fact, you probably won’t notice the extra weight.


  • Objective Lens: 32mm diameter
  • Magnification Rate: 2.5X
  • Reticle Type: ACSS CQB
  • Battery: CR2032
  • Field of View: 37.5 feet at 100 yards
  • Eye Relief Level: 2.7 inches
  • Diopter Adjustment: -2 to 2 DPT
  • Color: Matte black
  • Weight: 15.5 oz
  • Material Type: 6061 Aluminum
  • Length: 4.8 inches

Primary Arms 2.5X Compact AR15 Scope Pros & Cons


  • Rugged and tough.
  • Simple button layout.
  • Excellent mid and close-range scope.
  • Small and lightweight design.
  • Wide field of view.
  • Forgiving eye relief.
  • Quality illumination.
  • Great value for money.


  • Sometimes the field view gets busy.
  • Not so good over longer distances.
  • Cannot be used with iron sights.
  • Not the strongest magnification.

Looking for Other Quality Scope Options?

If so, then check out our reviews of the Best Rimfire Scopes, the Best Scopes for AR15 under 100 Dollars, the Best Deer Hunting Scopes, the Best Scout Scopes, or the Best Mini 14 Ranch Rifles on the market in 2023.

Or, take a look at our in-depth reviews of the Best 308 Rifles Scopes, the Best Mil Dot Scopes, the Best 300 Win Mag Scopes, the Best Air Rifle Scopes, as well as the Best Scopes for M&P 15-22 you can buy.


If you are on a budget and want to buy an affordable scope with mid-level features, this is a solid choice. When considering the price, the exceptional value for money is there for all to see. Is it the best compact scope on the market? No, it’s not, but it does merge value, reliability, and ruggedness. It’s also very adaptable and is compatible with most industry-standard ACOG mounts.

If you’ve just spent loads of money on a rifle and don’t want to pay a similar amount for a scope, then this is the type of scope that looks more expensive than it is. And although it might not have the best magnification, it still offers crystal clear views over shorter distances.

Happy and safe shooting.

5/5 - (65 votes)
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About Wayne Fletcher

Wayne is a 58 year old, very happily married father of two, now living in Northern California. He served our country for over ten years as a Mission Support Team Chief and weapons specialist in the Air Force. Starting off in the Lackland AFB, Texas boot camp, he progressed up the ranks until completing his final advanced technical training in Altus AFB, Oklahoma.

He has traveled extensively around the world, both with the Air Force and for pleasure.

Wayne was awarded the Air Force Commendation Medal, First Oak Leaf Cluster (second award), for his role during Project Urgent Fury, the rescue mission in Grenada. He has also been awarded Master Aviator Wings, the Armed Forces Expeditionary Medal, and the Combat Crew Badge.

He loves writing and telling his stories, and not only about firearms, but he also writes for a number of travel websites.

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