Enfield rifle with water trigger system
This Enfield would fire when enough water dripped (along the wire, I think) from the top can into the bottom can. It was used by the ANZAC forces at Gallipoli (WWI) to make the Turkish forces think they were still in the trenches while they were retreating.
Very clever. I want to make one! (With blanks, of course).
H/T: MP.net


With a bolt-action you obviously only get one shot. With a semi-auto, and a larger reservoir, you could have even more fun.
I’d never heard of this. Thanks.
Wow. That’s quite awesome.