[Abathar]

I don't know about crossbows still firing, but I believe it was the Aztecs that used poison darts that would still be deadly even after tens of thousands of years.

They built round vertical pipes with a smooth strait I.D. and had a very heavy plunger that was almost a perfect fit to the inside of the pipe. A simple lever would tip and drop the heavy weight into the pipe, which would drop a few feet and build up high air pressure that would then blow a poison dart down another piece of tubing toward whoever tripped the lever.

One expedition back in the 19th century supposedly tripped one and it hit the backpack of one of the team members, didn't hurt him but it still had the poison caked on the tip. They estimated the thing was almost two thousand years old.

[6SJ7]

A simple lever would tip and drop the heavy weight into the pipe, which would drop a few feet and build up high air pressure that would then blow a poison dart down another piece of tubing toward whoever tripped the lever.

Wow. I thought that kind of stuff was only in Indiana Jones!