The Holosun HS507K X2 Red Dot Sight with the ACSS Vulcan reticle (HS507K-X2-ACSS) is a 1x open-reflex pistol red dot sight on the Holosun K (RMSc) footprint, with a fixed red chevron aiming point inside a large guidance circle, in a housing measuring 1.6 × 0.98 × 0.95 in (40.6 × 24.9 × 24.1 mm) and weighing 1.0 oz (28 g).
It is the compact version of Holosun's ACSS Vulcan pistol optic: the same Primary Arms reticle on a footprint small enough for a slimline slide. The circle pulls the eye back to centre for speed, the chevron tip gives a finer hold than a round dot, and Shake Awake with last-setting recall keeps the sight ready without draining the cell. The aluminium housing is rated IP67 and tested to 5000G of vibration.
How It Compares
For a switchable circle-dot on the same footprint, the HS507K X2 red dot sight uses the Multi-Reticle System instead, and the HS407K X2 red dot sight is the plain 6 MOA dot option. In green, see the HE507K X2 with the ACSS Vulcan reticle. On a full-size slide, the HS507C X2 with the ACSS Vulcan reticle carries the same reticle on the RMR footprint with Solar Failsafe. Browse all RMSc footprint red dot sights and the wider Holosun pistol red dot sight range.
Ideal For
- Slimline and subcompact pistols with an RMSc-cut slide
- Section 1 long-barrelled pistols and revolvers held on a UK firearm certificate
- Shooters who want ACSS reacquisition speed without a full-size optic on the slide
- Airsoft GBB compacts and low-mounted training pistols
Key Features
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Reticle: ACSS Vulcan — red chevron aiming point inside a large guidance circle
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Footprint: Holosun K (RMSc) footprint, for RMSc-cut slides and RMSc-pattern plates
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Illumination: 12 brightness settings — 10 daylight and 2 night-vision compatible
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Electronics: Shake Awake motion activation with last-setting recall
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Battery: side-loading CR1632 tray, up to 50,000 hours of runtime
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Adjustment: 1 MOA per click, ±30 MOA windage and elevation, parallax-free
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Size: 1.6 × 0.98 × 0.95 in (40.6 × 24.9 × 24.1 mm), 1.0 oz (28 g)
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Housing: aluminium, IP67 rated and tested to 5000G
Technical Specifications
| Optic Type |
Open reflex pistol red dot sight, 1x (non-magnified) |
| Reticle |
ACSS Vulcan — chevron inside a guidance circle |
| Reticle Colour |
Red |
| Magnification |
1x, parallax-free |
| Footprint |
Holosun K footprint (RMSc pattern) |
| Illumination |
12 brightness settings — 10 daylight / 2 night-vision compatible |
| Battery |
CR1632 in a side-loading tray, up to 50,000 hours |
| Power Management |
Shake Awake motion activation with last-setting recall |
| Click Value |
1 MOA per click |
| Adjustment Range |
±30 MOA windage and elevation |
| Parallax |
Parallax-free |
| Dimensions |
1.6 × 0.98 × 0.95 in (40.6 × 24.9 × 24.1 mm) |
| Weight |
1.0 oz (28 g) |
| Housing |
Aluminium |
| Water Resistance |
IP67 water and dust resistant |
| Vibration Rating |
5000G |
| MPN |
HS507K-X2-ACSS |
What's Included
- Holosun HS507K-X2-ACSS red dot sight
- Multi-tool, lens cloth and user manual
UK Delivery & Support
Imported from the USA, duty paid by us, and dispatched tracked from the UK — nothing to pay on delivery — backed by UK-based support.
Frequently Asked Questions
What is the ACSS Vulcan reticle on the Holosun HS507K X2?
The ACSS Vulcan is a Primary Arms reticle that pairs a chevron aiming point with a large surrounding guidance circle. On the Holosun HS507K X2 ACSS the circle pulls the eye to centre for fast reacquisition, while the tip of the chevron gives a more precise hold than a round dot.
Is the Holosun HS507K X2 ACSS an RMR or an RMSc footprint optic?
The Holosun HS507K X2 ACSS uses the Holosun K footprint, which is the RMSc pattern, so it fits RMSc-cut slides and RMSc-pattern adapter plates. It is not an RMR-footprint optic; the RMR version of this reticle is the HS507C X2 ACSS.
Will the Holosun HS507K X2 ACSS fit a SIG P365 or a Glock 43X?
Both of those pistols use the RMSc optic cut, which matches the Holosun K footprint on the HS507K X2 ACSS, so the sight fits that cut directly. Confirm your slide is the optics-ready RMSc variant before ordering.
Does the Holosun HS507K X2 ACSS have solar power?
No. The Holosun HS507K X2 ACSS runs from a CR1632 cell alone. Shake Awake with last-setting recall is what supports the 50,000-hour runtime rating on the K-series; Solar Failsafe is fitted to the larger C-series models.
How much does the Holosun HS507K X2 ACSS weigh?
The Holosun HS507K X2 ACSS weighs 1.0 oz (28 g) and measures 1.6 × 0.98 × 0.95 in (40.6 × 24.9 × 24.1 mm), which is what allows it to sit on a slimline slide without unbalancing the pistol.
How tough is the Holosun HS507K X2 ACSS?
The Holosun HS507K X2 ACSS has an aluminium housing rated IP67 for water and dust and tested to 5000G of vibration, so slide reciprocation and British weather are both within its rating.
