How to Install a Glock Adapter for Holosun Sights

By Precision Optique | Published: 2026-10-19

Category: How-to Guides

Step-by-step guide to installing the Holosun HS-SMP-GLOCK adapter plate on a Glock pistol. Covers tools, alignment, torque, and common mistakes.

Quick answer

To install a Glock adapter for Holosun sights, use the HS-SMP-GLOCK plate, secure it with the provided screws at the correct torque, and verify the optic sits flat before final tightening.

Why the right adapter matters

The Holosun HS-SMP-GLOCK plate is designed specifically for Glock pistols (except 42/43) and Holosun 407C, 507C, and 508T sights. Using a universal plate can cause misalignment or poor contact, so matching the adapter to both your gun and optic is essential for a reliable mount.

This adapter replaces the factory rear sight plate on your Glock slide. It provides a precise interface that keeps the red dot secure under recoil. If you skip the correct plate, you risk the optic shifting or losing zero during use.

Tools you will need

You need a small flathead screwdriver or punch to remove the rear sight, a Torx T10 or T15 driver (depending on the optic), a torque wrench capable of 15-18 in-lbs, and blue Loctite. The HS-SMP-GLOCK plate comes with screws, but you should confirm they match your optic's thread pattern.

Installation steps

1. Unload and clear the pistol: Remove the magazine, lock the slide back, and visually confirm the chamber is empty. This is a non-negotiable safety step before any work on the slide. Never skip clearing the firearm. A live round during disassembly can cause serious injury.
2. Remove the rear sight assembly: Use a sight pusher or a brass punch and hammer to drift the rear sight out from left to right. If your Glock has a factory plastic sight, it may break during removal; replace it with a steel sight if you plan to co-witness. Mark the sight direction before removal. Installing it backwards can damage the dovetail.
3. Clean the slide recess: Wipe the optic cut area with isopropyl alcohol and a lint-free cloth. Remove all oil, debris, and old thread locker residue. A clean surface ensures the plate sits flat and the screws hold properly. Grease or dirt under the plate can cause the optic to loosen after a few rounds.
4. Position the HS-SMP-GLOCK plate: Place the plate into the slide recess. It should drop in without force. If it does not sit flush, check for debris or burrs. The plate orientation is marked; ensure the arrow points toward the muzzle. Do not hammer the plate into place. Forcing it can warp the plate or damage the slide.
5. Apply thread locker and install screws: Put one drop of blue Loctite on each screw thread. Hand-tighten the screws in a cross pattern (front left, rear right, front right, rear left) to distribute pressure evenly. Then torque to 15-18 in-lbs using a torque wrench. Over-tightening strips the screw heads or cracks the plate. Under-tightening lets the optic shift under recoil.
6. Mount the Holosun optic: Place the Holosun 407C, 507C, or 508T onto the plate. The screw holes should align without forcing. Apply blue Loctite to the optic screws and torque them to the manufacturer's specification (usually 12-15 in-lbs). If the screws do not align, do not force them. Check that the plate is seated correctly and the optic is the correct model.
7. Verify function and zero: Reassemble the pistol and function-check the slide cycle by hand. Then head to the range to zero the optic at your preferred distance (typically 25 yards). Recheck screw tightness after the first 50 rounds. Screws can settle after initial firing. A second torque check prevents the optic from coming loose mid-session.

Product details

Plaque adaptatrice Holosun HS-SMP-GLOCK: The HS-SMP-GLOCK plate is 47.6 mm long, 28.6 mm wide, and 3 mm thick, designed for Glock pistols except models 42/43. This slim profile ensures the optic sits low enough to co-witness with standard-height iron sights, improving accuracy without adding bulk.
Plaque adaptatrice Holosun HS-SMP-GLOCK