I have a Mossy 500 with the 20" barrel and longer 7 round mag tube. I currently have a green laser rifle sight mounted on top via a picatinny rail. I am considering changing the laser out for fixed front and rear sights but unable to find any that will work without doing some gunsmithing on it. I have one last idea. Does anyone know if Mossberg 500 12g Factory Ghost Ring Rear Sight and a Snap-on Fiber Optic Universal Front Sight For Shotgun Barrel 12/20 Ga would work together or like I said before just stick with my laser mounted rifle sight.