Another creation by my talented father: The Lucky Shot! [link]
The metal was awfully hard to cut (what would you expect from an army helmet) but it went without any problem. Other than dad drilled a hole in his thumb, but he says it didn't hurt.
The mortar round is made of solid wood and is screwed to the helmet liner underneath the actual shell. Some extra padding is preventing any damage the screw could possibly deal to my skull.
I've got an entire BLU Soldier cosplay ready, but I simply cannot find the time for a photoshoot, so it's coming whenever.