Review: Primary Arms 1X Compact Prism Scope

posted on July 22, 2018

Fixed-power, 1X red-dot optics are a popular sighting option for today’s AR-pattern rifles. With their simple sighting procedure (“put the red dot on the target and pull the trigger”) and uncomplicated reticle, they are a great choice for applications when fast target acquisition and a clear view of the target is necessary. One of the latest options on the market is a new roof-prism design from Primary Arms: the 1X Compact Prism Scope.

Most 1X red-dot sights cause issues with people like me who suffer from astigmatism. Conventional red-dot and holographic sights use mirrors and other optical devices to project a dot inside that optic, and because people with astigmatism have trouble resolving the focus of objects correctly, those types of optics don’t give us a red dot to aim with, they give us a small, irregular, figure-eight shaped aiming point that is hard to use effectively.

Roof-prism optics like the Primary Arms 1X Compact Prism Scope use a different optical system than red-dot or holographic optics. Rather than use mirrors or similar systems to focus the sight, they use a system much like the tried-and-true roof-prism optics in some binoculars and spotting scopes. As a result, the sight picture is much clearer and sharper for people with astigmatism.

Scopes using roof-prism optics work great, but up until now, they’ve been mainly offered in optics with low-power magnifications like 3X and 4X. These are great optics and that extra magnification comes in really handy at longer distances, but there is a trade-off. That extra magnification means that your field of view at closer ranges is a little bit narrower, and that means your target acquisition isn’t quite as fast.

This is where Primary Arms’ new 1X Compact Prism Scope comes in handy. Because it uses a roof-prism optical system, the sight picture, even with my astigmatism, is clear and free from blurring, leading to more-accurate shots at longer ranges, and because it’s a 1X optic, your field of view matches what your eyes see, allowing you to pick up new targets quickly.

The 1X Compact Prism scope comes with an extended-height Picatinny-rail mount to allow for good sight alignment with AR-pattern rifles and a lower-height mount for other rifles. The reticle has 11 illumination settings powered by a replaceable CR2032 battery, and I was able to see the difference the illumination made, even in the bright sunshine of a Florida summer morning. I attached the scope to one of my AR-15s and adjusted the focus dial on the back of the sight until the ACSS reticle was sharp. I then did a preliminary sight-in with a laser bore sight and headed to the range.

I sighted in the optic at 50 yards using the 1/2-MOA clicks on the turrets, and right away, I could see a difference compared to the 1X scope red dot I had been using. My old scope, a decent, inexpensive red dot, didn’t really give me a dot as a sight picture; it was more of a bright red dot with a red comet tail. This is not the case with the 1X Compact Prism Scope: Because the reticle is etched onto the glass of the optic and not projected into a mirror, my sight picture was clear, and the extra features of the ACSS reticle became readily apparent to me.

The ACSS reticle in the Primary Arms 1X Compact Prism Scope is designed to provide rapid hits in a variety of situations. The center chevron is calibrated to provide accurate sighting from point-blank distance out to 400 yards with most common AR calibers, and the outside edges of the horseshoe allow you to easily lead a target moving at walking pace. Another nice thing about the etched reticle in this scope is that it works perfectly fine with the batteries turned off, something that does NOT happen with a red-dot or holographic optic.

I was easily able to hold my shots into a 2-inch circle at 100 yards from a rest with this optic, and at 200 yards, I held everything inside of 5 inches. Where I found this optic to really work well, though, is in the fast-paced sport of 3-Gun. The horseshoe part of the reticle allowed me to quickly gets fast hits on-target at close distances, and the accuracy of the center chevron came in mighty handy when I had a tricky shot to make a precise shot to miss a no-shoot target further downrange.

The Primary Arms 1X Compact Prism scope is a godsend for people like me who suffer from astigmatism and yet prefer the wide field of view and fast transitions that a 1X scope provides. With all the features of other more expensive red-dot and holographic sights and an MSRP of $239.99, this sight is a great choice for someone looking for a solid, lightweight combat optic for their AR-15.


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