All good advice from fellow members above.
I'll tear it down when I first get a gun, to tune, change hammer and/or trigger, and remove machining chips (especially at the bottom of the screw holes), and roll over burrs. Then seldom do again. I flush periodically with Breakfree CLP (cleaner lubricant preservative), and let drain. That's it, it already gets re-lubricated with CLP at the same time.
If you want to tear down you may find these videos and tips helpful:
Factory Videos: Good New Model Ruger disassembly:
http://www.youtube.com/watch?v=UfOXBa8K8Ow
NM Reassembly (shows hammer plunger assembly too):
http://www.youtube.com/watch?v=3zEKDqwkgEs&feature=related
Factory OM disassembly/re-assembly video:
Ruger doesn't have an OM single six or Blackhawk video so choose the video for the Old Army which has the same lock work. Video at the bottom of the list, here: http://www.ruger.com/resources/videos.html?vidID=005039
View or request Owner's Manual here: http://ruger.com/service/productHistory.html#
GATE SPRING: A few tips based on my experiences:
1. To release the gate spring from the cross pin, the small tip screwdriver used as shown in video below is miraculously easy with just two hands or the frame can be held in a padded vise to really make it simple. A little practice with the technique is the key here.
2. The first disassembly is always the worst. The pins are supposed to be slip fit, if they aren't, the first time they come out they get a thorough polish (like they are in the video!) Never need a hammer, just a paper clip or punch to push them in and out with my fingers. See #8 below for things that make the pins hang up.
3. Bevel both sharp edges of the trigger/cyl bolt pin groove for ease of releasing the pesky spring.
If I'm not removing the cyl bolt, or gate spring, just trigger/transfer bar, I always leave the pin partially in the frame keeping the spring under tension, with pin sticking out on the loading gate side.
4. The current production guns have a new divot in the top of the trigger guard for the elbow of the fork in the spring for a better fit. Before that, some of the springs came filed on the elbow.
5. Leave cyl pin in the gun to avoid frustration while reassembling with transfer bar hanging up on firing pin preventing hammer from cocking.
6. Pawl spring must go in plunger 1st, you know that, but it's a common error.
7. Always unhook both legs of the trigger spring for reassembly of grip frame.
8. Always check the grip frame screw holes for machining chips left in them from threading the holes (especially stainless guns), and clean out if present. The two screw holes behind the trigger guard usually have huge rollover burrs from drilling the hammer pin hole and milling the frame. This will cause screws to screw in too tight and/or break off.
Install all five screws but do not cinch them tight. Align the grip frame edges flush with the cyl frame by tapping with the butt of a plastic handled screw driver. Tighten one trigger guard screw, then front screw and then one ear screw. Then tighten them all.
9. and lastly: MY SHORTCUT FOR REMOVING JUST HAMMER and/or PAWL:
Recognize, you do not need to hassle with the PESKY LOADING GATE SPRING, pull the trigger pin, OR trigger/transfer bar JUST to remove the hammer and pawl. Once you remove the grip frame, the hammer pin is the only other part you need to remove. After that, just pull the hammer back and all the way down, then depress the hammer plunger in the base of the hammer with a small tipped screwdriver to clear the trigger extension where the transfer bar connects to it. Let the hammer & pawl fall out. Install in reverse! Piece o' cake.