Thank you RKG....after the "fix" last year it never acted up again. The pistol was returned to the factory five years ago. I had another issue with it and I did open it up---I could never get that spring in the trigger in the right position...what a goofy set-up. Looks like they designed it to baffle us. IMHO these things should be designed to be relatively easy for an average guy to be able to service them. S & W fixed it up and then I started have the problems mention. I never tried to adjust the main spring tension for a lighter trigger, but when it was mis-firing (as mentioned before) I did tighten the strain screw.
The strain screw should always be, and have been, tightened all the way in. Some shooters wrongly loosen the strain screw to obtain a lighter double-action pull. But one of the problems with that is, the screw is then likely to become looser via recoil, to the point where misfires occur. Swap-out the mainspring for a lighter one if you must, but the strain screw should always be tight in the frame.
Sometimes you get what you pay for, sometimes you only pay more for what you get.
Three shots are not a "group"...they are a "few".
If the Bible is the literal, infallible, unerring word of God...where are all those witches I am supposed to kill? (Exodus 22:18)