I got my 15-22 back out to the range today and I'm pleased with the results.

In my first two magazines I got one failure in each one. But after that it was perfect. By the end of the session I had fired approximately 180 rounds with only two misfires. I cycled through four different brands of ammunition and three different magazines. No matter, past those two early failures it was all perfect.

I even loaded the misfires from the last session. They all shot perfectly as well.

I consider the problem solved. Whether or not it was too much lube near the firing pin and breech area, or whether the hammer pin was detached all along, I don't know. But having addressed both of these issues, my problems went away.

By the way I kept a close eye on the hammer pin to see if it would work its way out again. So far there is no sign that it has moved. But obviously I'll keep a close eye on it henceforth. If it moves again my first recourse will be to call S&W and assume the internal spring is broken. As a backup I'll replace the pin with the locking option discussed above. But so far so good.

Thanks much to all of you who offered suggestions. It was all very helpful to me.

Ray