Well I finally got an early model 48-4 almost new in box.Very nice gun. Paid to much but it has all accessories etc. I have taken down the high spots and it is much smoother now. The single action trigger pull is good but the double action is extremely heavy for my wife as a relatively new shooter.

The question I have is can you replace the main spring and/or rebound spring with a Wilson Combat or some other and still get reliable ignition? I also read on this site that some people have had problems with wolf spring kits.

I looked at some site of a well known gunsmith and if you sent your gun for a serious tuning they want to know if it will be a "duty" gun or "target" gun. That leads me to believe that reliable ignition with a lesser mainspring or reboung spring may not be reliable. Has anybody lightened the single/double pull and was successful?

I have a 48-4 that I have done some action work on. The best thing I can tell you is you can improve the DA pull, but don't expect it to be as light as a centerfire, it ain't gonna happen. The 22 mag takes a solid strike of the firing pin to fire, so you can experiment by reducing the mainspring tension until it becomes unreliable, and then turn the screw back in 1/2 turn, loctite it, and you should be good to go.
Also, some brands of 22 mag ammo are more sensitive than others, so remember to experiment with brands also.
The trigger rebound spring can be cut, or replaced with a reduced power spring also, again you will have to experiment to see how your 48 likes what you are doing.
My 48 is a range gun, so An occasional misfire in DA doesn't bother me, as I shoot it SA most of the time.
Lastly, remember to brush the chambers often, and brush under the extractor, you will get along a lot better with misfires by having it clean.