I aquired a 1917 Colt in a trade from a friend who had it rebuilt: ie. new barrel, reblued and timed. In the rebuild the gunsmith replaced the main spring and others inside with springs from a Python. It made a world of difference in the trigger pull. He warned that it might cause light hammer strikes but I have not had any FTF and it is a joy to shoot.

If you don't want to go that route or the expense invest in a therapy ball (I don't know it's correct name) that is used to strengthen the grip and fingers.