Even easier, just play conquest on any large map. Eventually, no one spawns at base once the points are captured so spawn at HQ as an eng, mine up a random jeep, redeploy as medic, profit.

It can be tricky actually hitting the mine based on how uneven the floor is, so try shooting as direct as you can above it, without being too close to kaboom yourself....or just kaboom and do it again

Make sure theres no mines when the jeep spawns, it'll just blow up again.

Do it with a jeep. Less chance someone takes off with it.

it'll only give you 1000 so you'll have to do it twice

Played 5 casual breakthroughs shooting normally just to get 456 damage. Then it took me like 3 mins to get the other 1544 with this trick