Honestly don't bother killing zombies with flashlights, you need to find a 2 shot melee weopon ie hatchet, katana, machete before you even bother killing zombies unless you find loot and need to stop to get it. Takes a little getting used to but once you learn all the loot spawns and easy routes you can simply avoid all the zombies and bug them out or sit on a fence untill you have more sprint. If you have questions about where or what to loot send me a PM I am more then happy to help other players to get a better population on this game.