More of an RAF speciality, the Mess Mortar is a much underrated weapon system. The beast is made from taping 5 empty food cans (normal size) together to form a hollow tube with baffles, and, obviously enough, I closed end. Projectiles vary from plastic bottles, to issue green socks. Detailed instructions are:
1. Open one tin normally and remove the lid, and punch two small holes in the base, one in the center and one at the edge, inside the rim. This is the base tin.
2. Open 4 tins normally, then half open the base of each and fold the flap out of the way to form a semi-circular opening - half the tin.
3. Tape the 4 half opened tins together with Black'n'Nasty (Duct Tape) - Open end to half open end, open end to half open end (turned through 90 degrees compared with previous) and so on, finishing in an open end.
4. Tape the half open end of this tube of tins to the open end of the base tin.
5. Buy some lighter fluid.
6. Squirt some (you'll need to experiment here) lighter fluid in to the center hole in the base. Shake and swing the thing hard to create a fuel / air mix inside the cylinder (the baffles created by the half opened ends help here). The trick is to get the size of squirt to mixing ratio right.
7. Hold a lighter to onw of the holes in the base. If you get anything other than a very very loud bang, and flame shooting from the end, shake some more, light again, then if no joy return to step 6.
8. Once you've got the mixture sorted, find a suitable non lethal projectile (duct tape covered socks are good) and go and get some target practice in.
9. BE CAREFUL - THESE THINGS CAN BE SURPRISINGLY POWERFUL. IF YOU'VE NEVER SEEN A GOOD ONE, YOU'LL BE SERIOUSLY AMAZED ONCE YOU GET IT WORKING PROPERLY.
Ownership of a Mess Mortar is (probably) an offense under the 2006 No-one is Allowed Fun Stuff legislation introduced by the bunch of cnuts we laughingly call a Government.