Is there a post or site that describes your procedure in more detail? I currently polish surfaces with toothpaste and a paper sack, install reduced power springs and install a set screw in the grip.
I’m not aware of any specific posts or sites which detail the process I described, but I’m sure there are some out there. It’s not a complicated mechanism, so establishing stops for excessive travel and reducing resistance is pretty straight forward. I’ll offer some detail here.
In any trigger, we can evaluate pre-travel, creep, overtravel, and pull weight - and subjective FEEL as a measure of polish and spring/sear design. Mil-spec AR triggers don’t have pre-travel, often have excessive creep, often have excessive overtravel, and have excessive pull weight.
Creep: The plug screw in the grip reduces creep by limiting the downward travel of the tail of the trigger - reducing how far the front of the trigger moves UP into the sear cutout in the hammer. The same creep reduction can be accomplished by reprofiling the bottom radius of the hammer, reducing the height of the sear, but doing so without creating an uneven sear engagement is more difficult than simply lifting the tail of the trigger.
Overtravel: the AR FCG has a lot of room for excessive overtravel, so the shooter has a “mushy” back wall in the trigger follow through. Great triggers feel like “breaking glass,” but AR triggers will moreso feel like “falling through ice,” largely because of the long overtravel they allow. We really only need the sear to travel the 20-25thousandths of sear engagement, then sufficiently farther to not drag on the bottom of the hammer. Like the creep, we have two options of reducing over travel: we can stop the front of the trigger from falling too far, or stop the back of the trigger from raising too far. So a set screw or a glob of JB weld - or shimstock JB welded in place - either under the front of the trigger or on the flat of the selector barrel - OR in these respective parts of the trigger itself - can provide positive stop for the overtravel.
Pull weight: Pull weight is relatively easy, at least getting down to 3-4.5lbs, especially using commercial, non-mil-surp ammo. Swap the springs with a JP yellow reduced power spring kit, and you’re there. Going lower can be challenging, due to the positive inclination sear angle, as the hammer spring always influences the total pull weight - but most folks don’t want to invest in stoning jigs to properly recut square sear angles, and most folks are terrified about “cutting through the hardening” of sear faces, and nobody wants to reharden the triggers for such a cheap job. So we tolerate the acceptable 3-4.5lb ballpark we end up with.
Trigger feel: polishing the pivot pins, the internal bores, and the sear faces, combined with the weight reduction, creep, and over travel reductions will vastly improve the trigger feel. When we reduce pull weight substantially, we can often start feeling the grittiness present in the sear face when they’re not well polished. Smoothing this out can dramatically improve the stronger feel, and make the shooter relatively unaware of the amount of sear travel they’re still moving.