Primary Arms GLX4 Series 6-24x50 FFP Riflescope

Any 6-24x50 riflescope is easily compared with peers in the same price bracket who
use a similar 4x erector tube to meet this specification. What’s most interesting, is
how each manufacturer has gone about making their internally similar scopes stand
out, and Primary Arms has been a little more creative with their turrets and reticle.

The build

The scope is built around a hard anodised, one-piece 30mm main tube that swells
out to the 50mm objective lens housing. This extends about 15mm beyond the glass
surface to offer some protection. The tube is smooth and doesn’t pick up dust from
your skin.

The central saddle carries windage to the right, elevation on top, and
parallax/illumination to the left. Both windage and elevation turrets feature central
locking buttons, that once set up, mean your zero is locked until you press the button
to rotate either dial. The instruction manual is comprehensive and explains the zero-
stop facility.

The scope runs milliradians/MRAD, so each click is 0.1 MRAD or 10mm at 100m.
There are 100 clicks per turn, which is 10 MRAD overall, and windage is marked left
and right of centre. The 41mm diameter dials are heavily knurled for grip and the
clicks are well-spaced, easy to see, audible, and tactile. Once zeroed, the turrets can
be removed with the supplied Allen keys to align all the markings, and you also gain
access to the bright red internal zero-stop setup. The patent-pending turrets
advertise hardened steel mechanics for long-life performance, and full rotations are
marked with a scale below the upper dial. Overall elevation travel is 17.7 mils, which
enables decent long-range dialling capability.

On the left

The left side parallax adjusts from 25m to infinity, with an entire 360º rotation needed
to span that range. This gives more precise control of parallax correction and focus,
making the scope suitable for smaller rimfire rifles and some airguns, assuming you
don’t intend to shoot at high magnification below that range. The dial is silent in
operation but a bit narrow, so your thumb and fingertips need to be used to adjust it.

The illumination control extends beyond the parallax dial and shows ten intensity
settings and intermediate off positions. Power is delivered by a CR2032 battery
under the end cap, which is finger accessible. To save battery life, the AutoLive
reticle illumination technology turns everything off after three minutes of no
movement. If it detects movement again, then the illumination is switched back on at
the same intensity. I think battery automation has to be expected as standard on
scopes these days, so well done Primary Arms!

To the rear

The very rear of the scope shows a fast-focus eyepiece that is rubberised for grip,
and the moulding pattern matches the machined profiles of the aluminium
elsewhere. The magnification collar follows a similar tactile pattern and rotates
clockwise from 6-24x mag, spanning just under 180º. There is a low-profile wing on
the collar that’s secured with Allen bolts and there are three possible mounting
positions for this to suit your needs.

The reticle is in the first focal plane (FFP), so all the markings correspond perfectly
with the external turrets, allowing you to measure, aim off, or dial corrections with
certainty at any magnification. It resolves well once the eyepiece focus is set up, and
the image offers 95% edge-to-edge clarity with flat focus. Primary Arms state that the
eye relief is 3.5-3.6” (90mm), and this is my preferred specification on target-oriented
scopes, as it coincides with a more forgiving eye box and a slightly broader
comparative field of view. There is no tunnelling at low magnification.

Primary advertise an optimized mechanical and optical design that virtually
eliminates your eye’s perception of the scope tube and extends the field of view
nearly edge-to-edge. The ocular body is just 40mm in external diameter, with very
little physical bulk surrounding the 31.5mm lens, and in reality, this does go some
way to assist with the concept.

Fully multi-coated, low-dispersion glassware is used, and the image quality is great
in daylight. However, it’s not a low-light hunting scope and never suggests it will be.
The reticle complexity is advantageous in target or daytime varminting environments,
and some will like the chevron-shaped aimpoint over the more common crosshair or
floating dot.

Illumination capability is a huge benefit on any FFP scope, as it means on full
intensity, at low magnification, you can still see the tiny reticle and use it as a fast
and intuitive aimpoint on an optic that seeks to impress.

The tracking was good, and it passed the box test with ease. I really liked the
assured, tactile feel of the clicks and trusted the scope enough to use it on a
relatively critical rifle test where accuracy and precision needed proving.

Conclusion

6-24x50 optics are very common, so it takes inventive design to appeal. The
glassware is competitive considering the price point and optical specification, but I
would say that Primary Arms has delivered mechanics a little above average. All
while maintaining modest dimensions without bulk.