Charles,
Marlinman has it right. Getting rid of that horribly heavy trigger return spring makes a big difference.
Besides very light stoning to make sure the trigger sear surfaces are smooth (they usually are, I've found), there are two ways to do a trigger job on a Roller.
You can either silver solder a thin shim or build up with a spot of heli-arc weld to make a pad just in front of the hammer sear surface to lessen the sear engagement. Some people say an alternate is to drill a hole just smaller than 0.060" piano wire and tap a short piece of it into the hole. Either one of these methods may prevent the trigger sear from contacting the hammer sear surface. Then dress down the built-up area until the sear barely catches. Measure the trigger pull and continue to stone the area until the trigger pull increases to the weight you want.
The other way is to stone a taper on the top edge of the trigger sear. In this method, the metal immediately behind the trigger sear acts as the built-up area and lessens the sear engagement. In this case, stone carefully until the triger pull gets down to the point you want. If you go too far, you get to build up the trigger sear, shape it, harden it, and restart the process.
Lightening the mainspring will also lighten the trigger, but that's more advanced.
I have RB triggers done both ways, and they both work well. On my .43 RB, the trigger pull came from 12-15 lbs. to 4-5 lbs. with just the installation of the piano wire return spring.
Clarence
