2280 damage done
Heh, reminds me of two funny moments:
1) 1.8k~ damage as a Spy in a single life:
I went up to the battlements in the last area of Gold Rush, but there weren't any snipers. There was an engineer on the ground, so I get a headshot on him, but due to the distance, I had to wait until the aim re-straightened. By the time I got another shot off, between the dispenser and him taking cover, he had fully healed. So I kept trying for about 15 headshots before giving up. Lots of damage.
2) 4k+ damage as a Demo in a single life:
Badwater: I was on defensive, and eight heavies and four medics were on offensive. I couldn't kill them with my stickies, due to how quicky they were healed, but they never killed me since I wasn't a threat. So I ended up racking up a crapload of damage. Really helped when I got a medic to Kritz me and all eight stickies hit :D