Originally Posted by
NSB
Is sounds like a significant headspace issue....with those rounds you're attempting to fire. If the firing pin is free, and you can push it forward with your finger so that it protrudes, and the hammer is falling, the primer just isn't in the right spot when the pin gets there due to either the case too far from the pin or the case is moving forward as it gets hit. Don't take this the wrong way or anything, but are you sure this used gun you got is actually barreled with a .348 Win? Has it been rebarreled where the headspace could be way off? How does a factory round fit in the chamber? It's kind of odd that it won't even dent the primer based on what you're describing with the firing pin moving and all.