Also those posts often recommend replacement springs but since this model is downsized I'm not sure all the recommended Colt SAA kits are applicable.
Howdy
Replacing springs alone is not an action job. Replacing springs can tend to highlight other problems. Before replacing springs, unnecessary friction between moving parts should be removed.
First, consider buying this book. Absolutely the best book on the market about tuning and repairing a single action Colt. Almost everything in it will also apply to Uberti replicas. You can also find this book on Amazon and at Brownells.
http://www.gunbooks.com/colt_sa.html
Next, work the action a bazillion times.
Don't cock the hammer and pull the trigger so the hammer falls, just cock the hammer and gently lower it a bazillion times.
See if the action improves.
After working the action a whole bunch of times, take it apart.
Be sure you have some good quality hollow ground screwdrivers. Standard hardware store screw drivers with tapered tips can tend to rise up out of the slot and bugger the screw. Uberti screws are soft, and are generally torqued in very tight. You want good quality hollow ground screwdrivers that will not climb up out of the slots.
Brownells Magna-Tip screwdrivers are the best there are. They are guaranteed if you break or bend a tip that Brownells will replace them. You can buy huge sets of Magna-Tip screwdriver from Brownells. You can also buy sets specifically set up for specific guns. This set is set up for the Colt SAA and will also work for any Uberti clone.
https://www.brownells.com/gunsmith-...colt-single-action-screwdriver-prod25458.aspx
Now, lock your Dremel tool away in a drawer and do not even think about using it.
Look inside the frame for any obvious burrs left over from the machining process that the moving parts could be rubbing against. Remove any such burrs with a sharp blade or very fine file.
Now look at the lockwork parts.
These are Colt parts, but the Uberti parts are very similar. The upper arrow is pointing to the surface of the hammer that rubs against the frame as the hammer is cocked. You want this surface and the same surface on the other side of the hammer to be very smooth. Contrary to popular opinion, you do not necessarily need this surface to be polished to a mirror finish. Polishing it to a mirror finish can remove too much metal and affect the fit. What you want is to remove any 'peaks' left behind by rough tool marks, but leave any 'valleys' that may be left behind. This way, the smoothed peaks will be the bearing surface, while the valleys can retain oil.
You want to lap the surfaces of the hammer on a hard stone.
This is a good stone. Notice you can use it with water instead of honing oil.
https://www.brownells.com/gunsmith-...ng/stones/ceramic-bench-stones-prod12609.aspx
Place the stone on a stable surface. A workbench is a good place. Wet the stone with water. Place the hammer flat on the stone, with just the round part on the stone. Leave the rest of the hammer hanging over the side of the stone. Use light finger pressure to rug the hammer against the stone. A circular motion is best, but you might want to just go back and forth so you don't rub away any blue that might be on the visible sides of the hammer. As you lap the hammer, dirty metal residue will coat the stone. Wash it away with fresh water. Do both sides of the hammer. It should be nice and smooth, but not necessarily a mirror finish.
The second arrow is pointing to the hammer cam. This is a separate pressed in piece in a Colt, it is a cast in feature on an Uberti hammer. The hook of the bolt legs catches on the upper curve of the cam as the hammer is cocked. When the hammer falls, the wedge shaped portion of the cam shoves one of the legs of the bolt to the side, allowing the bolt to stay up and engaged in the cylinder locking slots. Be sure the wedge shaped surface of the cam is smooth, without any bumps or ridges.
The arrow in this photo is pointing to the bolt. The underside of the bolt leg that rides against the hammer cam should be very smooth too. It will probably have a radiused edge to engage the cam. Don't change the shape, just make sure the surface is nice and smooth. You can do this by gently rolling the surface of the bolt on the stone while rubbing it. Don't overdo it, the bolt is a piece of spring steel. It needs to flex. Don't remove enough metal to seriously thin the bolt leg, just smooth it a bit.
.
That's really it for a quick tune up of a Colt or Uberti. There are other things you can do, but this is a good start.
