Collimator Holosun HS507K-X2 Red ACSS Vulcan Dot

Primary Arms by Holosun HE507K‑X2 Red ACSS Vulcan Dot pistol reflex sight is the latest iteration of a miniature MRDS designed for subcompact pistols. This compact unit delivers the fast target acquisition expected from reflex sights while remaining extremely compact for comfortable concealed carry. The X2 upgrade repositions the buttons horizontally for easier operation despite the small footprint. The sight features the innovative red ACSS Vulcan Dot reticle (dot with a dashed ring).

Holosun reflex sights — affordable shooting optics

The sight housing is precision‑machined from 7075 aluminum. The unit is light and durable at just 28 g. The mounting footprint is adapted to the Shield RMSc standard for subcompact pistols. Unlike the previous model, the X2 series uses a new horizontal button layout that most users find more comfortable and intuitive. The sight is rated IP67 for weather resistance and temporary immersion, and the anodized finish improves wear and scratch resistance. The X2 model also includes a Lock Mode button lock to prevent accidental changes.

Primary Arms by Holosun HE507K‑X2 Red ACSS Vulcan Dot — compact sight for subcompacts

The HE507K‑X2 uses lenses with multi‑layer anti‑reflective coatings to deliver high light transmission and a clean, sharp, parallax‑free image. The electronics and LED are shock and recoil resistant and built to perform reliably in harsh field conditions. This pistol reflex incorporates the innovative ACSS Vulcan aiming solution.

How is the ACSS Vulcan Dot different from a classic dot or dot+ring?

ACSS Vulcan Dot reimagines reflex aiming: the red dot is supported by a dashed, partial ring (optional), which helps quickly center the reticle on target. If the dot is lost, the ring outline at the lens edge assists intuitive correction and quick reacquisition. A sight with the ACSS Vulcan Dot reticle provides a noticeable advantage over mechanical sights during fast engagements at longer ranges.

Power comes from a CR1632 battery, which the manufacturer rates for up to 50,000 hours of operation at brightness level 6. Users may select automatic brightness or manually choose intensity across 10 daylight settings and 2 NV‑compatible settings. The impressive runtime (up to 50,000 hours) is supported by the Shake Awake system, which automatically turns the LED off during inactivity and places the sight into sleep mode.