Actually, you don't have to replace the ramp. My father, who I am reluctant to call an "old timer", grew up before scopes. His solution was to take a "3-cornered file" and file the step of the ramp that shoots too high very slowly and carefully until it shoots at the required point of impact.
The problem with this solution is that it only works for a single load, unless, by luck, you find a second load that shoots to the same point of impact. If you get a second ramp, however, you can adjust it for a second load.
dclark