The Holosun 509MNT-1.63-PIC is a genuine Holosun 1.63 in (41.4 mm) Picatinny mount for 509T-footprint enclosed red dot sights — the HS509T X2, HE509T X2 and HE509T-X2-GD. At that height the dot sits at lower-1/3 co-witness on an AR-pattern flat-top rail.
Lower-1/3 is the standard height for a rifle dot: the optic sits high enough for a natural, head-up shooting position, and AR-height iron sights still appear in the bottom third of the window as a backup rather than blocking the middle of it.
How It Compares
For a shotgun, rimfire or other low-rail host, the 509T Picatinny mount in 0.82in low profile keeps the dot closer to the bore. To fit a 509T optic to a pistol slide instead, see the 509PLT-507C mounting plate. Browse all red dot sight mounts and straight-pull rifle optics, or read our guide to co-witness heights.
Ideal For
- Civilian Service Rifle and practical rifle on straight-pull AR-pattern carbines
- Rifles that keep flip-up iron sights as a backup behind the dot
- Airsoft AR builds where a head-up shooting position matters
- Moving a 509T optic off a pistol slide onto a flat-top rifle rail
Key Features
-
Optic Footprint: Holosun 509T rear-lug footprint, not RMR and not RMSc
-
Height: 1.63 in (41.4 mm) optical centreline — lower-1/3 co-witness
-
Rail: clamps to any Picatinny MIL-STD-1913 rail section
-
Hardware: mounting hardware supplied
Technical Specifications
| Optic Footprint |
Holosun 509T footprint (HS509T / HE509T) |
| Mount Height |
1.63 in (41.4 mm) — lower-1/3 co-witness |
| Rail |
Picatinny (MIL-STD-1913) |
| Hardware |
Mounting hardware included |
| MPN / UPC |
509MNT-1.63-PIC / 810047071082 |
What's Included
- Holosun 509MNT-1.63-PIC Picatinny mount
- Mounting hardware
Warranty
Covered by Holosun's manufacturer warranty, handled in the UK by Xtreme Tactical.
UK Delivery & Support
UK-stocked and dispatched tracked from our UK warehouse — no import duties or customs delays — backed by UK-based support and Holosun's warranty.
Frequently Asked Questions
Which optics fit the Holosun 509MNT-1.63-PIC mount?
The Holosun 509MNT-1.63-PIC fits optics with the Holosun 509T footprint, which means the HS509T X2, the HE509T X2 and the HE509T-X2-GD. It does not fit RMR-footprint optics such as the 507C, and it does not fit RMSc-footprint optics such as the 507K.
Will my iron sights still work with the Holosun 509MNT-1.63-PIC?
Yes. At 1.63 in (41.4 mm) the Holosun 509MNT-1.63-PIC gives a lower-1/3 co-witness, so standard AR-height iron sights appear in the bottom third of the window and remain usable as a backup without obscuring the dot.
Should I choose the 1.63in or the 0.82in Holosun 509T Picatinny mount?
Choose the 1.63 in (41.4 mm) mount for AR-pattern rifles, where it gives lower-1/3 co-witness. Choose the 0.82 in (20.8 mm) mount for shotguns, rimfires and other low-rail hosts where you want the dot close to the bore.
What rail does the Holosun 509MNT-1.63-PIC fit?
The Holosun 509MNT-1.63-PIC clamps to any Picatinny rail cut to MIL-STD-1913, which includes the flat-top receiver rail on AR-pattern rifles.
