Due to receiver variations, you may need to modify the length of screws with a file or a grinder.
Caution: The M4x.7screws can start screwing into the 8-40 holes and cross-thread the receiver holes. Use the correct screws.
This precision-machined adapter plate allows for the mounting of the Holosun 507K, 407K and any variant with the same footprint to a Mossberg 500, 590 or Shockwave that has a drilled and tapped receiver. We take immense pride in the aesthetics and quality of parts we produce. Each part is inspected with calibrated precision measuring tools and checked against a model print to maintain tight tolerances.
Fits: Mossberg 500, 590 or Shockwave that has a drilled and tapped receiver. Holosun 507K, 407K and any variant with the same footprint. All mounting hardware needed comes with the order.
Precision Machined 4140 alloy steel, coated with a copper phosphate to aid in corrosion resistance.
Install instructions for The CNC Pros Mossberg Shotgun adapter plate:
1- Make sure the surfaces and threads are clean and free from debris. Apply a light coat of oil or grease to the adapter plate to prevent rusting.
2- Loctite 222 (purple) is recommended. Absolutely under no circumstances should any red, green, or blue thread lockers be used.
3- Put a drop of 222 on the internal threads and on the thread's screws.
4- Use the supplied M4x.7 and 8-40 screws.
5- Very Important Note: Use a reliable torque driver set 10-13 IN. LBS
6- Allow to cure for 24 hours.