Quoted from PinballTom113:I will check out all these areas and see what I find.
Thank you all for your responses!
Any area where the ball touches sharp metal is suspect. Is there a metal strip ball guide with sharp edge that the ball crashes into? What about the two sharp edges at the apron exit point? Can the ball crash into the sharp edges on the apron exit point?
A couple of my pins have a thin metal ball guide strip at the end of the shooter lane. On one pin, the ball was staying nice and shiny. On the other pin, the ball was a nicked up mess. The reason: On one of the pins, the ball guide was tucked in behind the shooter rail and the ball left the shooter lane cleanly.
On the other pin, the ball guide was sticking out from behind the shooter rail. As a result, on every shot, the ball collided with the guide that was sticking out and in the ball's way. That ball guide's sharp edge just destroyed that ball.