As far as I know, no. There isnt anything you can really do to shorten the trigger pull.
You can lighten the pull somewhat by swapping out the trigger spring. It is housed in the backstrap of the grip. My P85 has a plug in the bottom of the grip that is retained by a roll pin. Drift out the pin and you can remove the plug, trigger spring and hammer strut. Swap the spring with a lighter one and reassemble. Its pretty easy and I did a write up on how a few years back.
http://www.rugerforum.com/phpBB3/viewtopic.php?t=148741
http://www.rugerforum.com/phpBB3/viewtopic.php?f=2&t=148741
However. Doing this does make it possible/likely that you will get light primer strikes with some kinds of ammo. I ended up putting the spring back to almost the same weight as stock to keep it reliable.