I built my AR back during the height of the gun-buying craze post-Sandy Hook, so I really didn't have too many options when it came to acquiring parts. I ended up with a DPMS parts kit, which has worked flawlessly so far, but included a standard AR trigger, which, like most standard triggers, sucks. I'll end up getting a lighter spring kit for it eventually, but some of the problem that I had with it was how grainy the pull was. Since I work at a hobby store, it came to me to try out some of the stuff that was sitting, quite literally, in front of my face.
This is 80w fluid for RC truck shock absorbers. I dumped some into the trigger springs, in addition to putting some on a few coils of the buffer spring in order to eliminate the rattle of it in the tube when firing. This stuff accomplished both the task of smoothing the trigger pull and neutralizing the buffer rattle, and the stuff is fairly inexpensive ($4 for this bottle). I haven't tried other applications yet, but this stuff is a new option for me
This is 80w fluid for RC truck shock absorbers. I dumped some into the trigger springs, in addition to putting some on a few coils of the buffer spring in order to eliminate the rattle of it in the tube when firing. This stuff accomplished both the task of smoothing the trigger pull and neutralizing the buffer rattle, and the stuff is fairly inexpensive ($4 for this bottle). I haven't tried other applications yet, but this stuff is a new option for me