Originally Posted by Jim H

SW9F is a first-generation Sigma. I have its sibling SW40F. My 40F ran great right out of the box, but after 500 rounds or so the light strikes began. It seemed to be ammo-specific for a while, but eventually it would not light off any round.

I called S&W, and the authorized a return for repairs. The replaced the striker, cleaned it up and returned it at no charge. I think the striker and tip had been redesigned after I bought my 40F, and they put in the updated striker.

No light strikes since.

If there is any doubt, call S&W Customer Service and explain what is happening. Most members on this board have had wonderful experiences with S&W service.

Good luck!