The Holosun HS507K X2 ACSS (HS507K-X2-ACSS) is a 1x open reflex pistol red dot on the Holosun K footprint, carrying the Primary Arms ACSS Vulcan reticle — a red chevron inside a large guidance circle.
The ACSS Vulcan is the reason to pick this over a plain dot. The circle drags the eye to the centre of the window on the draw, and the tip of the chevron then gives a finer hold than any round dot of the same visual weight.
The housing is aluminium, 1.6 x 0.98 x 0.95 in and 1.0 oz, rated IP67 against water and dust and tested to 5000G of vibration. A CR1632 loads from the side for up to 50,000 hours, with Shake Awake and last-setting recall so the sight wakes at the brightness you left it on. There are 12 brightness settings, 10 for daylight and 2 for night vision, and the turrets move 1 MOA per click with 30 MOA of travel either way. It is parallax-free.
This is the compact member of the ACSS Vulcan family, sized for a slimline slide rather than a full-size one. Two things to keep in mind: the ACSS reticle is a Primary Arms exclusive configuration rather than a standard Holosun catalogue item, and the K-series has no solar panel — Solar Failsafe belongs to the larger C-series sights, so this one runs on the cell alone.
Why shooters choose the HS507K X2 ACSS
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Reticle — ACSS Vulcan — a red chevron inside a large guidance circle
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Footprint — Holosun K, the RMSc pattern, for RMSc-cut slides and plates
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Illumination — 12 settings — 10 daylight and 2 night-vision compatible
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Power — side-loading CR1632 up to 50,000 hours, with Shake Awake and last-setting recall
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Adjustment — 1 MOA per click, 30 MOA of travel each way, parallax-free
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Size — 1.6 x 0.98 x 0.95 in and 1.0 oz, so a slim slide stays balanced
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Durability — aluminium housing rated IP67 and tested to 5000G
What the HS507K X2 ACSS fits
It fits slides cut for the RMSc pattern and RMSc-pattern adapter plates, which covers most slimline optics-ready pistols. For a switchable circle-dot on the same footprint see the HS507K X2 MRS, and on a full-size slide with a solar panel the HS507C X3 is the larger equivalent. More small-footprint optics sit in RMSc footprint red dot sights.
Specifications
| Type |
Open reflex pistol red dot sight, 1x |
| Reticle |
ACSS Vulcan chevron and guidance circle |
| Reticle colour |
Red |
| Footprint |
Holosun K (RMSc pattern) |
| Illumination |
10 daylight / 2 night vision settings |
| Battery |
CR1632 in a side-loading tray, up to 50,000 hours |
| Power management |
Shake Awake with last-setting recall |
| Adjustment |
1 MOA per click, 30 MOA travel each way |
| Parallax |
Parallax-free |
| Dimensions |
1.6 x 0.98 x 0.95 in (40.6 x 24.9 x 24.1 mm) |
| Weight |
1.0 oz (28 g) |
| Durability |
IP67, 5000G |
| MPN |
HS507K-X2-ACSS |
A chevron and a circle in an ounce of aluminium is a lot of aiming system for a slimline slide. Order the HS507K X2 ACSS today — imported from the USA with all duties paid by us and dispatched tracked from the UK in 7–10 business days, with nothing to pay on delivery.
Explore more: RMSc Footprint Red Dot Sights, HS507 ProMax or browse all Holosun
