There is a little plunger which is used to disassemble the bolt. Sometimes, this gets stuck in the depressed position and the rifle won't fire. If it was mine, I would toss the plunger and use a punch when I wanted to disassemble. If it is for a customer, free up the plunger and there you have it. To me, any feature which can produce a failure to fire when things go wrong is a feature which should be removed.