A few tips:
1. Leave the cyl out of the gun until completely assembled but put the cyl pin so the hammer moves back and forth easily; that way you cam observe the cyl latch. If it loses tension you'll immediately know the plunger has slipped off the latch.
2. Always unhook both legs of the trigger spring for reassembly, it's easier to get the spring behind the trigger shelf for assembly.
3. The hammer pin cannalure and long screw can go on either side of the hammer as long they're both on the same side.
4. The cyl hand spring to the left side of the hammer goes plunger first. Also, you can put a small magnet over the spring to hold it in the hole and just let the grip frame push the magnet out of the way as the grip frame ear slips into position over the hole.
5. 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. Check for ease of hammer movement to be sure it's not rubbing on grip frame ears.
NOTE: While you have the grip frame off, it's always good to examine the upper end of all the grip frame screws blind screw holes in the main frame (especially stainless guns) for thread shavings that weren't cleaned out from the factory and get crammed in there by the screws.
Also check the two trigger guard screw holes where they are exposed by the milling cut if your grip frame has the two projections that go into the main frame (the New Vaquero and New FT BH guns no longer have these projections and milling cuts). Almost always there will be a huge flat 'roll-over' burr in each hole from the milling cuts that expose the holes. If they are present they generally cause the 1st 1/8" of removing those two screws to take extra effort to unscrew and can cause screws to screw in too tight and/or break off. You'll need to break off the burrs and pick them out with a dental pick or equivalent tool.
6. MY SHORTCUT FOR REMOVING JUST HAMMER and/or PAWL in New Models:
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. Reinstall the hammer and pawl back in the same way they came out. Push the plunger in by pushing it against the trigger extension just like you did with the tip of the small screwdriver, and the hammer will slip by the trigger extension. Piece o' cake.
Occasionally a hammer change that just barely cocks is because it's hitting the back of the slot in the grip frame. I have had to slightly lengthen the slot with a few file strokes.
If either the trigger or hammer pin are snug fits, after they're removed the first time, it's the opportunity to polish them so they're slip fits to put back in and remove the next time.
7. GATE SPRING: A few tips based on my experiences:
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. The '3rd hand' jigs take more time to use.
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.
Bevel both sharp edges of the groove in the trigger/cyl bolt pin 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.
Factory Video - New Model Ruger Disassembly:
http://www.youtube.com/watch?v=UfOXBa8K8Ow
Factory Video - NM Reassembly (shows hammer plunger assembly too):
http://www.youtube.com/watch?v=3zEKDqwkgEs&feature=related
8. Three easy ways to replace hammer spring and spring perch at this site: http://www.cylindersmith.com/Ruger-spring.html
