Meat Locker Chapter 4 - I found this to be the easiest way to "Come and get it" just start it up grab the 4-5 Artillery flares available in the Bunker. Gives you plenty of chances to hit n' miss.
Overall have patience corral a decent horde to a reasonable area and Rain down that Righteous Death to the Undead Horde.
Video provided by Iron Goat Gaming.