Steps:
- Start a game alone on Mannhattan
- Buy knockback rage, buy some crit canteens and resistances
- Farm the 1st wave of gatecrashers for rage using crits and let them cap the gates
- Run back to spawn
- Wait for the bomb carrier to get about a meter from the hatch
- Taunt to activate rage and shoot the carrier down (I used the Tomislav for faster spinup) make sure you only start firing when the bomb bot is going to take the bomb off his back

This took me only like 3 attempts using this method, and I was unlucky, you could easily have the achievement in 10 mins or less.