I haven't, but I'd like to know more about it. At the house in my hometown, there are some donated balls serving out the years as house balls, and one of these is a green Manhattan Rubber. The fingers and thumb are beveled in the way you describe. Either I can't bowl with a ball like that, or it's not close to what I'd need for a fit.
What's the purpose of drilling a ball this way? It would seem you wouldn't be able to get much lift on the ball if the finger holes didn't have some kind of lip on them.
Jess
