Jack question for old piano

[Doug Renz]

I am starting to get more involved with minor repairs on actions for
customers and tonight
I installed a jack for an old upright piano, and when I set the jack
in the action, the hammer
was not resting in the same place as the other hammers, how can I
regulate or adjust this
hammer when the jack length is slightly longer than the other? It
sounds ok, maybe a little
quieter because of the decreased blow distance. Thanks for the advice
to a new tuner
starting to do repairs.

Doug