ACSS stands for Advanced Combined Sighting System. It is Primary Arms' family of reticles that combine a fast close-range aiming point, bullet-drop holds, wind holds and range-finding marks in one sight picture, so you can hit at different distances without touching the turrets.
Each ACSS reticle is calibrated for a particular type of cartridge and a particular unit (yards, metres or mils). Choosing the right one matters more than choosing the scope. Here is how the system works, which versions we stock, and where it fits a UK rifle.
Key takeaways
- ACSS means Advanced Combined Sighting System, Primary Arms' own reticle family.
- Most ACSS reticles pair a horseshoe for close-range speed with a chevron whose tip is a precise aiming point.
- Drop holds are calibrated for a type of cartridge, such as 5.56/.308 or 9mm, so check them against your own load.
- Versions come in yards, metres or mils: Raptor, Aurora, Nova, Griffin, Cyclops and Gemini each suit a different job.
- In an SFP scope the holds are only correct at the calibrated magnification, usually maximum.
How an ACSS reticle works
Most ACSS reticles are built from the same parts:
- Horseshoe: a large open ring you put over the target at close range, where speed matters more than precision.
- Chevron: an upside-down V inside the horseshoe. Its tip is a fine aiming point that does not cover the target, which a large dot would.
- Drop holds: a ladder of marks or small chevrons below the centre, each for a set distance.
- Wind holds: short marks or dots either side of each drop hold for crosswind.
- Ranging marks: bars scaled to a typical target width or height, so you can estimate distance from how much of the bar the target fills.
The ACSS Cyclops shows how it fits together. Primary Arms describes zeroing the chevron tip at 50 yd (46 m), which puts the round about 1 inch (25 mm) high at 100 yd and back on the chevron tip at 200 yd (183 m). Further holds go out to 400 yd (366 m) for 5.56 NATO and 300 yd (274 m) for slower cartridges such as 7.62x39, with four ranging bars for 200, 300 and 400 yd.
The ACSS versions you will see
Each version is designed for a type of optic and a unit. The names used in our listings come straight from Primary Arms:
| Reticle | Designed for | Where you will find it |
|---|---|---|
| ACSS Cyclops | 1x prism sights; horseshoe, chevron and holds for 5.56 and 7.62x39 | GLx 1X MicroPrism and SLx 1X MicroPrismT |
| ACSS Gemini 9mm | Pistol-calibre carbines | SLx 1X MicroPrismT Gemini |
| ACSS Raptor 5.56/.308 Yard | Fixed-power prisms and FFP LPVOs, holds in yards | SLx 3X MicroPrism, PLxC 1-8x24 FFP |
| ACSS Aurora | 5.56 holds in metres, or mils | SLx 1-6x24 Aurora 5.56 Meter, SLx 5X MicroPrism Aurora MIL |
| ACSS Nova (Fiber Wire) | SFP LPVOs, 5.56/.308, bright fibre-wire illumination | SLx 1-6x24 Gen IV, PLxC 1-8x24 SFP |
| ACSS Griffin | Mil-based, for dialling and precise holds | SLx 1-10x28 Griffin M10S, PLxC 1-8x24 and 1.5-12x36 Griffin MIL |
Calibre labels such as "5.56/.308" mean the drop holds are close enough for both cartridges at the distances the reticle covers, when fired from the barrel lengths the maker assumed. They are not a guarantee for every load.
Why shooters rate it
- Fast holdovers: the drop and wind marks are already in the glass, so you hold instead of dialling.
- One reticle for close and far: the horseshoe handles close targets and the chevron and ladder handle distance.
- Works without a battery: the reticle is a physical pattern in the optic (etched glass in the prisms), so it is still there if the illumination fails.
The limits to know
Every drop hold assumes a muzzle velocity, bullet and zero distance. Change the barrel length, bullet weight or zero and the 400 mark may really be a 360 or a 440. The answer costs one range session: shoot each hold at its distance, note where it really lands, and you have a verified system. The guide to reticle types explains how BDC-style reticles compare with plain and mil-grid designs.
Focal plane matters too. In a second focal plane LPVO such as the SLx 1-6x24, the holds are only correct at the calibrated magnification, usually 6x. In a first focal plane scope such as the PLxC 1-8x24 FFP, they are correct at every power. See FFP vs SFP explained.
UK note
In Great Britain, self-loading and pump-action rifles are prohibited unless chambered for .22 rimfire, under section 5(1)(ab) of the Firearms Act 1968. So the 5.56 and 9mm holds on ACSS reticles are usually used in the UK on straight-pull, bolt-action or lever-action rifles, whose barrel lengths and loads may differ from what the reticle assumes. Northern Ireland has its own legislation, the Firearms (Northern Ireland) Order 2004. Check what your certificate allows with your firearms licensing department. On a metric range, the Aurora 5.56 Meter version saves you converting yard holds.
Is ACSS right for you?
If you shoot at a mix of distances and would rather hold than dial, ACSS is excellent. It suits practical rifle, gallery rifle and general range use. If you only shoot at one distance, or you stalk inside 200 m, a plain duplex or a simple dot will be quicker and less cluttered. For magnified builds, see our guides to the best LPVO rifle scopes and prism scopes.
Frequently asked questions
What does ACSS stand for?
Advanced Combined Sighting System. It is Primary Arms' name for its reticles that combine close-range, drop, wind and ranging features.
Will ACSS 5.56 holds work with .223 Remington?
Roughly, because the two cartridges fly similarly, but the holds assume a particular velocity. Confirm each hold on paper at its distance with your own rifle and ammunition before relying on it.
Which ACSS reticle should I choose?
Match it to your cartridge and units: Aurora 5.56 Meter for metric ranges, Raptor for yard-based holds, Griffin for mil-based dialling, Gemini for 9mm carbines and Cyclops for a 1x prism.
Does the ACSS reticle work without batteries?
Yes. The reticle is a physical pattern, not a projected dot, so it stays visible with the illumination off. Illumination makes it faster to see against dark or busy backgrounds.
Shop this guide
- Primary Arms Prism Scopes — 1x, 3x and 5x MicroPrisms with ACSS reticles.
- Primary Arms LPVO Rifle Scopes — SLx and PLxC LPVOs with Nova, Aurora, Raptor and Griffin.
- Primary Arms Optics — the full range.
