Remove your Fire Control Group, clean and grease the sears, pins and the bottom curve of the hammer. This will help smooth out the pull. If you want to know how to re-install the FCG, check this thread. You might have to also remove the right hand bolt release to get the hammer back in-
Installing an AR Fire Control Group (Trigger & Hammer)
Grease it up and dry fire your rifle. Not only will this help break in your trigger, it's good practice