Our Extreme Duty rear sight will fit new style S&W K, L, and N frame revolvers made from 1993-1994 to the present (factory drilled and tapped for a scope mount). We recommend getting the Extreme Duty rear sight only to start with. You can install the Extreme Duty rear sight and shoot a test target at a measured distance with your existing front sight. You can then use the following front sight height formula to calculate what your front sight height should be:
In order to calculate this adjustment, you take the sight radius times impact distance, and divide by the target distance in inches, which will then equal your sight height change
(Sight Radius * Impact Distance)/Target Distance = Sight Height Change ==> Make sure all of your measurements are in inches!!
Example: Your gun shoots 2 inches low, at 15 yards (540 inches). Your sight radius is 6.9 inches, your front sight height is .210 inches. (6.9" * 2")/540" = .026" shorter sight needed.
Then you take your current site height minus change required. .210" - .026", tells you that your new sight height should be .180" tall. (.184" to be exact)
Once you know what yourfront sight height should be you can order one of our .250" or .300" tall sights or contact us for a custom front sight made to your specifications from a blank.