I have built 7 ar's and have used either Bushmaster or RRA match triggers in each.  I have been told that you can clip and bend a couple of springs and then insert a setscrew in the screw hole for the grip above the grip screw to lighten the trigger pull and shorten the pull.  I seen the article at one time posted somewhere but can not find it.  Anyone know this procedure?  where can I find it?

To save all of the headaches, just buy a new trigger set up to your liking.