Primary Arms GLX4 Series 6-24x50 FFP Riflescope


Any riflescope with a 6-24x50 specification is easily compared and contrasted with its direct peers who use a similar 4x erector tube to meet this specification in the same price bracket. What’s most interesting is how each manufacturer goes about making their internally similar scopes stand out and Primary Arms have been a little more creative with their turrets and reticle system. The scope is built around a hard anodised one-piece 30mm maintube that swells out to the 50mm objective lens housing which 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 feature central locking buttons that once set up, mean your zero positions 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 0.1mRad or 10mm at 100 metres on target. There are 100 clicks per turn which is ten mRad overall and windage is marked left and right of centre. The 41mm diameter dials are heavily knurled for grip and the click re well-spaced allowing great tactile feel and audible perception. This adjusts fast, secure, intuitive intuitive and the white engraved visual display is also clearly marked. Once zeroed, the turrets can be removed with supplied Allen keys to align all markings, and this also allows access to the bright red internal zero stop setup which is all fully explained in the instructions. The Patent-pending turrets advertise hardened steel mechanics to retain long life performance and full rotations are marked with a vernier scale below the upper dial. Overall elevation travel is 17.7 mils which enables decent long range dialling capability.

The left side parallax adjust from 25m to infinity with an entire 360-degree rotation needed to span that range. This gives more precise control of parallax correction and focus and makes the scope suitable for smaller rimfire rifles and some airguns, if you don’t intend to shoot at high magnification below that range. The dial is silent in operation although compact and needs thumb/fingertips rather than a full grip to access it. the illumination control extends beyond the parallax dial with ten intensity settings and intermediate off positions on the FFP reticle within. Power is delivered by a CR2032 battery under the end cap which is finger accessible. AutoLive™ reticle illumination technology turns illumination off after three minutes motionless to save battery life and automatically turns illumination back on again at the slightest motion with the same intensity. I think battery automation has to be expected as standard on scopes these days because it’s so easy to otherwise lose all charge so well done, Primary Arms!

The very rear of the scope shows a fast focus eyepiece for reticle focus, it’s 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 magnification in a clockwise direction spanning just under 180 degrees. There is a low-profile wing/tag on the collar that’s Allen screwed in place and there are three possible mounting positions for this to suit your needs. I quite like it because it’s a great tactile interface without being excessively long or bulky and as a chamfered wing shape, doesn’t snag as easily as a simple post design.

The reticle is in the first focal plane so all subdivisions and aim off marks correspond perfectly with the external turrets allowing you to measure, aim off or dial off corrections with certainty at any magnification. It’s resolves well once the eyepiece focus is set up and the image offers 95% edge to edge clarity with flat focus. Primary Arms state the eye relief is 3.5-3.6” which equates to about 90mm, and this is my preferred specification on target-oriented scopes as it coincides with a more forgiving eyebox and slightly broader comparative field of view. There is no tunnelling at low magnification. “Primary” advertise an optimized mechanical and optical design which virtually eliminates your eye’s perception of the scope tube and extends the field of view nearly edge-to-edge. This become apparent as 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 multicoated low dispersion glassware is used which is to be expected and the image quality is great in daylight but 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 more distinct chevron centre marker rather than the most usual crosshair or floating dot.

The 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 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 on a relatively critical rifle test where accuracy and precision needed proof.


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



Magnification 6-24
Objective lens diameter 50mm
Ocular lens diameter 31.5mm
Main Tube Diameter 30mm
Reticle Athena BPR Mil FFP
Eye Relief 90mm / 3.5" - 3.6"
Exit Pupil 8.10mm - 2.20mm
Field of view @100 yards 15.20ft at 6x / 4.20ft at 24x
Click Value 0.1mRad / 10mm @100m
Total Elevation travel 17.7 MIL
Total Windage Travel 11.8 MIL
Illuminated Reticle Yes, 10 intensity settings
Overall length 390mm / 15.3”
Weight 695gr / 24.5oz
Protection Fog, Water, Dust and Shock resistant, Lifetime Warranty, IP67