Deformers

Load up Local Games, add 7 Dummies with cn_LB and Choose "Battle Butte" as the map, then choose the Striker Ability (using any skin) as you spawn in the map ram into each enemy from left to right. You'll have a continuous momentum and you'll get about 80 kills per match if you get the hang of it. Since the Online servers are dead this achievement is extremely difficult to get in online mode.