CQA Trigger
Google 15 minute AR15 trigger job. My CQA started out with a gritty 8lib trigger, you wouldn't believe the machining marks on the sear surfaces. Just lightly polished to take out some imperfections, and viola 5.5 lbs. 300rds later trigger pull is still the same. However, I do have a spare trigger assy and will monitor for wear/change of pull.
If you choose this path, go slow and reassemble and check often, Don't change angles or engagement.