Back in the old days it was called "Bore-Safe", centrifugal force moved a steel block to lineup the explosive train. Not sure how they do it today but with a High-Explosive Point-Detonating (PD) fuse you need for it to be safe when the crew slams it into the closed breech block. I remember driving up to a 155 (M-109?) when the doors flew open and everyone was headed for the woods. That's just what they did, blew a little chuck out of the PD fuse and smoked up the inside. I seem to remember that it took about a 100 yards to arm, been a long time ago so that could be wrong.



http://www.google.com/patents?id=m61iAAAAEBAJ&dq=impact+fuse+%22bore+safe%22

Last edited by Michael Petrov; 07/30/07 02:43 PM.
MP Sadly Deceased as of 2/17/2014