If you're making a sniper then all you need is a travel stop and perhaps polish the ramp on the trigger plate and the rubbing point of the sear if it's needed. MOst of the time these surfaces are already quite smooth and polished. A spot that isn't often thought about is point of the sear and the end of the hammer lug. Those should also be polished to a mirror shine and the corner of the hammer lug slightly rounded over by this polishing.
A set of oil or water stones will do a lovely job of the inititial polishing and if you have an 8000 grit water stone then it'll leave a mirror like finish. Otherwise an oil stone and then finish with 600 wet or dry used with a bit of oil then work up to 1000 grit and then the BACK of the 1000 grit paper (it is quite abrasive but smoother than the front) and finish it with some mag wheel or chrome polish used on some file card like paper. By this time you should be able to easily see your reflection in the surface or sear and lug ends.
I had a "Paintball God" moment once.
Like Al Bundy's Polk High football moment I live on
for the slim chance of repeating that one time
miracle in some small way.........