Maybe you guys can help me figure out this problem. My chinese sks is giving me troubles. Sometimes I pull the trigger and "click" no boom. I have cleaned the thing very well, all parts slide smoothly. Today I tried some new ammo, cheap ammo. The first five rounds did not fire. The next seven or eight rounds fired great. When I looked at the rounds that didn't fire, it did not look like the firing pin made a mark on the bullet. I have had this trouble before, so I bought a new firing pin a few days ago. After firing about thirty rounds, probably ten did not fire. Then I installed the new firing pin. The first try, "click" then the next ten fired perfectly. In the past, I would look at the shell that did not fire, and I could see where the firing pen dented the bullet, but it didn't fire. However they have always fired the second time. Today, the rounds did not have a mark where the firing pin should hit. weird. Could it be the ammo? What else could cause this? Anyone else have this problem? Thanks for your help/opinion.