How to measure dovetail for sights?

[pl_2ic]

OK. I need to replace the front sight on one of my pistols, but it is an out of production pistol, so I can't just call the manufacturer...

I will remove the old one and measure it, but what dimensions do I need? Top of the dovetail (narrowest)? Or bottom of the dovetail (widest)?

 

[guntech]

You need the width and the angle and how deep it is cut..

 

[art.h]

Sometimes the average of the wide, narrow dimension will give you a ballpark figure for one of the standard dovetails, ie 3/8. But it may not give you satisfactory info.