hammer bore distance

[Cal Munson]

Hello List,

I have gotten some hammers bored recently and have discovered in  
putting them on that the bore distance is about 1/4 inch greater than  
on the old set.     Using a let-off jig, a small level and a gauge to  
measure the string height, I checked my hunch and  it appears that  
the bore is indeed 1/4 inch too much (shank does not get all the way  
up to perpendicular)

I am wondering what  would be considered  reasonable tolerances in  
the ideal bore distance?

Cal Munson