I keep reading about people changing triggers in new ARs. I can understand if you are building a high dollar long range rifle but I doubt most of us need a $200 trigger in our AR. I learned long ago that a little polish and about 15 minutes on most guns can make a huge improvement on a stock trigger. I do this with most of my guns not just ARs. What I am talking about is polishing not sanding, not grinding on a trigger, or removing metal. It's different on different guns, on a Glock I polish the trigger bar and connector but on most guns I just polish the hammer and sear engagements. On my two ARs I just polished the sear engagements on the hammer. I am talking about regular car polish not anything with any grit to it. After polishing the sear engagement on the hammer I then put a dab of polish on the hammer sear engagement. With the lower separated from the upper and while catching the hammer with one hand I pull the trigger with the other hand. I repeat this several times until I am happy with the pull. I then clean every thing and add a drop of oil, work it some more and then clean up the excess oil. This may reduce the pull a couple pounds but mostly it gets rid of the grittiness and makes a smooth clean breaking trigger.