Description

The HS510C is Holosun’s large-window open reflex and the sight most of its competitors get compared to. The open frame gives a wide, unobstructed view of the target instead of the tunnel feel of a tube sight, and a titanium alloy hood arches over the emitter so the exposed lens survives being knocked around. The Multi-Reticle System switches between a 2 MOA dot for precision, a 65 MOA circle for speed, and the combined circle-dot at the push of a button, all projected by the same LED, so changing reticles never costs the shooter a zero.

Power is the part that sets it apart in this price class. Solar Failsafe runs the sight off its solar panel whenever there is enough light and falls back to the battery when there is not, and Shake Awake puts the optic to sleep when the rifle sits still and wakes it the instant it moves, so it can be left on in the safe indefinitely. Twelve brightness settings cover full daylight down to two night vision levels, and the battery tray loads from the side, so a dead cell gets swapped without pulling the optic off the rifle. It ships on its own quick-detach Picatinny mount and comes back off without a tool and without losing zero.

Key Features

• Optic Type: Open reflex red dot
• Magnification: 1x
• Window Size: 0.91″ x 1.26″
• Reticle: Selectable 2 MOA dot, 65 MOA circle, or 65 MOA circle-dot
• Illumination: Red Super LED, 650nm; 12 settings (10 daylight, 2 night vision)
• Adjustment Click Value: 0.5 MOA
• Total W/E Travel: 50 MOA
• Eye Relief: Unlimited
• Field of View: Unlimited
• Parallax: Free
• Weight: 8.3 oz with QD mount
• Length: 3.3″
• Power: (1) CR2032 included, solar backup, approx. 50,000 hr battery life
• Weatherproofing: IP67, shockproof
• Mounts Included: QD M1913 Picatinny
• Warranty: Limited lifetime on housing and optics; 10 years on the LED
• Country of Manufacture: Not published

Optical & Mechanical Specifications

• Lens Coatings: Multi-coated
• Housing Material & Finish: Aluminum, matte black anodized, titanium alloy protective hood
• Dimensions: 3.3″ L x 1.6″ W x 1.8″ H
• Optical Centerline Height: 1.41″ over the rail
• Battery Tray: Side loading

Use Case

• AR-15 and modern sporting rifle builds
• Pistol caliber carbines
• Defensive shotguns
• Home defense
• Practical rifle competition

Compatibility & Fitment

Rail Space Required Approx. 3.5″ of continuous Picatinny for the mount footprint. Leave room behind it if a magnifier will be added later; the HM3X needs roughly another 4.5″.

Host Platform Fit Flat-top AR-15 and AR-10 upper receivers, and any Picatinny-railed rifle or shotgun. Clearance should be verified on rifles with a fixed front sight base, since the front post will sit in the lower portion of the window.

Co-Witness Height Absolute co-witness at a 1.41″ dot height, so the dot and standard AR iron sights share the same line of sight. Holosun sells a spacer separately that raises the dot to 1.63″ for a lower 1/3 co-witness; it is not included with this sight.

Does Not Fit This is not a plate-mounted pistol optic. It mounts only by its own Picatinny QD mount and does not fit RMR, ACRO, RMSc, or K-series slide cuts, or M-LOK rails.

Compliance & Legal Notes

• No FFL Required: Optics are not firearms; this item ships directly to the buyer with no FFL transfer.
• Export Restricted: Electro-optic sighting devices are subject to U.S. export control. Domestic shipping only; no international orders.
• California Prop 65: This product carries a California Proposition 65 warning (Zanders Prop 65 code A2).
• Buyer Responsibility: The buyer is responsible for confirming this optic is legal in their jurisdiction.

Box Contains

• HS510C open reflex sight
• QD Picatinny mount
• CR2032 battery