I wouldn't tinker with an existing trigger. Are you using a stock mil spec trigger? That would be helpful to know.
That said, ACT with 4.5LB spring, BCM PNT, hell even PSA Enhanced polished are all better than a stock mil spec trigger.
Personally, most of my rifles now have either an SSA, SSA-E or LaRue MBT's in them. I have a couple that still have ACT's so I'll be changing them out soon enough.
ETA, you COULD go with something like a reduced power spring but IME it doesn't make a bad trigger better, just lighter.