Quick answer

Mount your red dot by first confirming the optic footprint matches your slide or adapter plate, then degrease the screw threads, apply blue threadlocker, and torque the plate and optic screws to the manufacturer's specs. For a Holosun EPS on a Glock 43X MOS or Hellcat OSP, use a compatible adapter plate like the DPP Titanium plate for the EPS footprint.

Why the right adapter plate matters

The Glock 43X MOS and Hellcat OSP use different slide cuts, and most micro red dots do not share the same footprint. The Holosun EPS uses the Holosun EPS footprint, which is not the same as the RMSc or Shield footprint found on many micro pistols. An adapter plate bridges that gap, but it must be machined to the correct tolerances; a loose or poorly fitting plate will not hold zero and can damage the slide or optic.

Material choice affects weight and durability. Aluminum plates are lighter and adequate for most carry setups, while titanium plates offer greater strength and corrosion resistance. The DPP Titanium adapter plate for the Holosun EPS is available in both aluminum and titanium, so you can pick based on your priorities.

When to use a plate versus direct mount

Some slides are cut directly for a specific footprint, such as the RMSc, and require no plate for compatible optics. If your optic matches the slide cut exactly, you can mount it directly. However, if you are adding a Holosun EPS to a Glock 43X MOS or Hellcat OSP, you will need an adapter plate unless the slide has been custom-milled for the EPS footprint.

A direct mount is generally more secure and sits lower, but it limits you to one footprint. An adapter plate adds versatility and lets you use a wider range of optics, but it adds a small amount of height and introduces one more set of screws to maintain.

Step-by-step mounting process

  1. Confirm compatibility: Check that your optic's footprint matches the adapter plate or slide cut. For a Holosun EPS on a Glock 43X MOS or Hellcat OSP, use a plate designed for the EPS footprint, such as the DPP Titanium adapter plate. Common mistake: assuming the slide cut is universal; the Glock MOS and Hellcat OSP have different screw patterns and plate requirements. Always test-fit the plate to the slide before installing screws.
  2. Degrease all screws and threaded holes: Use isopropyl alcohol and a clean patch to remove oil and debris from the plate screws, optic screws, and the threaded holes in the slide and plate. Common mistake: skipping this step, which prevents threadlocker from bonding and leads to loose screws under recoil. Let parts air-dry completely before applying threadlocker.
  3. Apply blue threadlocker: Place a small drop of blue (removable) threadlocker on the threads of each plate screw. Avoid getting threadlocker on the plate surface or in the optic's internals. Common mistake: using red threadlocker, which can be difficult to remove later and may require heat. Blue threadlocker is sufficient for most range and carry use.
  4. Torque the plate screws: Set your torque wrench to the plate manufacturer's recommended value (often around 15–20 inch-pounds for micro pistols, but verify with your specific plate and slide). Tighten in a cross pattern to seat the plate evenly. Common mistake: over-tightening, which can strip aluminum threads or warp the plate. If no torque spec is provided, tighten snugly and check after firing.
  5. Mount the optic: Place the optic on the plate, aligning the screw holes. Apply a small amount of blue threadlocker to the optic screws, then torque them to the optic manufacturer's specification (commonly 15–20 inch-pounds). Common mistake: using screws that are too long, which can protrude into the slide and bind the action. Verify the optic sits flush and does not wobble before tightening.
  6. Witness mark and verify: Use a paint pen to mark the screw heads and plate edges so you can detect any movement. Rack the slide several times to ensure the optic does not interfere with the extractor or ejection. Common mistake: forgetting to check for thread protrusion into the slide channel. Re-check witness marks after the first range session.
  7. Zero the optic: At the range, start at 10 yards and adjust the dot to coincide with the point of impact. Use small adjustments and confirm with a few rounds. Common mistake: zeroing with a loose optic; ensure all screws are tight before adjusting. Re-torque screws after 50–100 rounds and re-check zero.

Product facts

  • DPP Titanium Adapter Plate for Glock 43X/48 MOS Hellcat OSP Holosun EPS: DPP Titanium adapter plate designed for mounting a Holosun EPS footprint optic on Glock 43X/48 MOS, Hellcat OSP, and similar compatible slides. This plate lets you mount a Holosun EPS on your micro pistol without custom milling.

    DPP Titanium Adapter Plate for Glock 43X/48 MOS Hellcat OSP Holosun EPS

    DPP Titanium Adapter Plate for Glock 43X/48 MOS Hellcat OSP Holosun EPS