Primary Arms SLx 1-6x24 Gen IV Review

A generic BDC reticle gives a shooter a stack of holdover hashes and leaves the rest of the work, ranging a target and estimating a moving target's lead, to be done in the shooter's head. The ACSS Aurora reticle etched into this scope folds all three tasks into the glass at once: bracket-style ranging references sized to an average torso, yard-marked holdover dots calibrated to 5.56 NATO and .308 Winchester, and lead lines for a target moving across the shooter's field of view.

The trade for that capability is density. Where a duplex or a simple BDC reticle is uncluttered by design, the Aurora reticle puts real information on the glass at every magnification, and a shooter who has not learned which part of the pattern to use for which task will find the extra marks slow down a fast shot rather than speed it up. Eleven illumination settings help isolate the centre aiming point from the rest of the pattern in bright light, but the reticle itself is a genuinely different object from the one on a cheaper LPVO, not a decorated version of the same idea.

A 24 mm objective is a deliberately modest choice on a scope meant to live at low magnification, and the numbers show why that is the right call rather than a compromise.

Primary Arms builds this scope on a 30 mm tube with a 24 mm objective, which needs comparatively little ring height and is one of the practical advantages of a compact LPVO over a long range scope. Check what ring height a 24 mm objective needs on a 30 mm tube before ordering rings, and consider a cantilever mount if the rifle's rail position leaves the scope too far back for proper eye relief at 1x.

The dovetail-compatible magnification ring accepts a throw lever, and on a scope built around fast transitions between 1x and 6x, using one is worth doing rather than skipping: finding a bare ring quickly with a gloved hand under time pressure is slower and less certain than finding a lever.

The honest limitation of this scope is not the optics, which owner-review consensus rates well for the price. It is the reticle's own design trade. The ACSS Aurora pattern is busier on the glass than a plain duplex or BDC reticle, and a shooter who has not deliberately learned which reference points apply to ranging, which apply to holdover and which apply to a moving lead will find the extra information slows a fast shot rather than speeding it up. This is a real cost, not a minor one, on a scope whose whole purpose at 1x is speed.

The second real limitation is cartridge specificity. The yard-calibrated holdover dots and ranging brackets are built around 5.56 NATO and .308 Winchester specifically. A shooter running a materially different cartridge and load will find the reticle's shape correct but its calibrated distances wrong, which is a limitation of a calibrated reticle rather than a defect, and worth knowing before buying into the system.

Two directions, depending on whether the reticle complexity or the price is the thing you would trade away.

The Vortex Strike Eagle 1-6x24 Second Focal Plane Riflescope, BDC3 MOA is a genuinely cheaper LPVO on the same 1-6x24 layout with a simpler BDC3 reticle rather than a calibrated ranging system, the right choice for a shooter who wants a plain centre hold and occasional holdover marks without the reticle density. The Swampfox Arrowhead 1-6x24 SFP LPVO, Green BDC, 30mm undercuts both on price with a green illuminated reticle that reads well against foliage. For a shooter who has decided the ACSS approach is worth the learning curve but wants first focal plane subtension at every power rather than second, the Vortex Viper PST Gen II 1-6x24 Second Focal Plane Riflescope, VMR-2 MOA is the genuine step up, at close to double the price.