I just added a Williams WGRS receiver sight to my BC carbine. I made a few measurements to try to determine the ideal front sight height and here they are. The barrel diameter at the rear sight is 1.1". I measured the height from the top of the barrel to the center of the WGRS sight allowing for it's adjustment range of .4" to .55" above the barrel and so figured the barrel radius of .505" plus the sight height of .4"-.55" and I'll need a front sight height to be between .905" and 1.055" or averaged to .980" as measured from the centerline of the bore to the center of the front sight's bead. The barrel diameter at the front sight is .7", so the radius is .35" and the distance from the top of the barrel to the center of the original front sight is .47", so I end up with a height of .82". To place the front sight in the middle of the rear sights adjustment range, the distance from the centerline of the bore to the center of the bead on the front sight should be .980" or .160" taller than the .820" I have now. Measured from the bottom of the dovetail, the original front sight is .570", the tallest offered be Williams. They do however sell a .250" riser which can be used to add height to the front sight. Given the need for .160" taller than the .570" sight, or .730" I believe the ideal front sight height used in combination with the .250" riser would be .480", but they are only available in either .450" or .500" so I'm thinking the riser plus the .450" sight would be my best bet.
Before I order anything however, I plan to shoot the rifle using the new WGRS sight with the original front sight just to see where the loads I'm using are going to hit.
Don