Based on that info and my experience this is what I would do. Too light a hammer spring (main spring) will cause the misfires, they will happen more in double action mode and might never happen in single action. I put a spring kit in mine and had misfires with even one weight lighter hammer spring. I left the original hammer spring in the gun and put in the lightest trigger spring. This gave me a 3.5 lb trigger pull in single action and I do not care about double action because I have to cock it to hit what I am aiming at.
Call Ruger and order a factory hammer spring and leave the trigger spring alone (assuming it is not to light for you). You can do it yourself, just follow the disassembly instructions in manual (have Ruger send you a manual if you do not have it). It is 10 minute job (maybe 30 the first time) and the instuctions are very clear. When you remove the hammer spring from bar that runs through it, put one end lightly in a vise and use visegrips to push the metal plate down and remove the pin and then let the tension off the spring. Assembly new spring in reverse order.
Good Luck!!!!
