Assuming the guns are repros, there are several books on tuning SA revolvers, including one by Jerry Kuhnhausen. I usually use a Dremel tool to feather the cylinder bolt spring, but leave the trigger (side of the) spring alone. The spring part of the bolt itself, where it contacts the hammer can be feathered also, but make sure this is done from the inside. Smooth the other side and the part of the frame it rubs against. Then the cam on the hammer can be stoned a bit to reduce spring flexing.
Break the edges on the cylinder bolt so it doesn't gouge the cylinder. The gun should be timed so the bolt drops into the locking notch leade rather than right between notches, but this is a job for a professional. If you just eliminate the gouges, you will have done well.
Taking some off the sides of the mainspring is a good idea and will reduce both cocking effort and trigger pull. A light stoning on the sear part of the trigger and on the hammer full cock notch will help a lot, but be careful not to cut through the case hardening unless you have the means to reharden.
IF the guns are original, DON'T DO ANYTHING!
Jim
