Nem, Disassemble your 39. Remove the bolt. Look at the rear chamber near the top. Use something like a dental probe to feel for a burr. Then look at the firing pin. It should be profiled where the farthest point forward is on the bottom edge (when oriented right side up). Look for a shiny spot or burr there. It should not be so profiled it comes to a point. Just enough to clear the rear most chamber edge. Cases will reveal if the firing pin is not striking close enough to the edge. Now look at the bolt. Push the firing pin fully forward. The retention pin (looks like a golf ball marker) should allow the firing pin movement with minimal friction. The older models don't have this pin. It might (unlikely) that the rention pin is too loose and it allows the firing pin's forward edge to become misaligned as it travels forward. The firing pin should also project far enough forward of the bolt face to make a good dent. I had a 39 with the rebounding hammer that required some filing on the underside firing pin projections that limit forward travel. I think I took about .030" off and it never had a problem again. Your problem is not uncommon with the rebounding hammer 39's. I like the safety but the rebounding hammer seems to increase the likelyhood of FTF. I've never had a FTF with my pre-safety 39's.