Measure your shotgun's rib width before purchasing a magnetic shotgun sight. An accurate measurement helps you select a sight designed to fit the rib securely.
Steps to Measure Shotgun Rib Width
- Make the shotgun safe. Unload the shotgun completely, open the action, and verify that the chamber and magazine are empty.
- Locate the mounting area. Identify where the sight will sit on the rib, typically near the existing front bead. Measure at that location. Do not assume the rib has the same width along its entire length.
- Measure the full rib width. Use calipers to measure across the outer edges of the rib. A ruler with fine graduations is an alternative. Do not measure only the narrow, flat surface along the center of a wider rib.
- Check sight compatibility. Compare your measurement with the manufacturer's specified rib-width range. Also verify compatibility with the rib's material and profile.
Choose a Sight That Fits Your Shotgun
Shotgun sights use different mounting systems and fit different rib widths. A magnetic sight must match the rib dimensions specified by its manufacturer. A replacement front bead may instead require a specific thread size or mounting method.
Use our Shotgun Rib Width Reference for additional fitment information. If you are replacing a threaded front bead, see the Shotgun Bead Thread Reference.
Once you have identified the required dimensions and mounting style, browse our shotgun sights to find options suited to your application.