YIKES! of all the grenades that I have dug up on Okinawa I have never done that. Easier to just unscrew the fuse and dump the powder out and place the primer on the powder and light it to blow the primer then screw them back together. This is still not safe by all means. It took a Japanese glass smoke grenade to go off in my face after i hit it with my digger, not to mention being confined in one of the tunnels while the tunnel filled with smoke to bring me back to reality. This was due us finding intact Cyanide Glass Grenades few months prior. So I thought that I had hit a cyanide grenade when it went off. I didn't cave hunt for almost a year after that incident. The cracked glass smoke grenade is still on display at the Battle of Okinawa Museum where I have to see it every year I go back LOL. David