>
>> Your physics doesn't add up.  If "all the energy" goes into the
>> excess lead, it will presumably be converted to kinetic energy
>> of that lead causing it to fly off.

Well, OK.  How about "half the energy" goes into the excess
lead, and (the equal and opposite) half goes into the board.
The board goes flying off in the opposite direction, about
0.1 mm due to its relative mass... :)

Barry

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