Load up mission start on ONI sword base with cowbell on. Immediatly run up the ramp to your right and kill the elite, then sprint past everyone else, trying not to kill anyone until you get to the little garage like place with the target designator. Pick it up, and run into cover and keep just running into the wall to trigger a checkpoint. Now, call an airstrike right outside the doors, where you just ran from. You can get 10-15 heavy weapons kills this way. Reload checkpoint and repeat. You should get silver in Campaign Splash Damage 10 minutes.
If you vote down at least tell why.
Thanks to W1LLYMAN for bringing my attention that I did not name the commendation.