I have no idea what could be wrong. There are times when the firing pin strikes the rim, that's all it does, no bullet down range. If I recock it, just raising the bolt up and back down, it will fire. One day I lost count on how many times I tried to get it to fire on one particular round but it wouldn't fire. I rechambered the round three times and would recock it, but it just wasn't going to fire. Sometimes I can shoot 20 plus without any issues and then it happens. It's always just one round and never consecutive rounds. I looked around for a stronger spring, but have not been able to locate one. Any suggestions.