For reliable ignition, I only used Federal primers when reloading for my 686 with the Wolff reduced power mainspring, since Winchester and CCI produced too many misfires. Can't recall now but at least 5-10%. Federal primers have the softest cup among Winchester, CCI and Federal. Have not tried Dominion. Notice the way FEDERAL packs their primers in huge boxes with a lot of distance between individual primers, I think that is because their primers are really sensitive to impact, again, due to softer cups.
Replaced the trigger return spring with the middle one in the Wolff Kit. The lightest spring felt too light. Even with the middle spring, the trigger still felt too slow in returning, but that was just a mental thing, the trigger always returned reliably. Make sure you have the proper screwdriver when you open up your revolver's sideplate, or you may screw-up the screw heads and or slip and scratch your frame. Wolff spring kit is the best DIY mod you can do and the most cost-effective.
Have sold those two 686's and haven't done my current 686 yet. It and the GP100 are on the to-do list.