I have found a great place to farm Hunting Rifle kills. The problem I found with this achievement is that ammunition is sparse whenever you locate one, making the Shotgun a wiser tactical choice. Well, I've found a Checkpoint with a Hunting Rifle (16 rounds) and infinite enemies to kill.
## Please note, the DLC "The Writer" is required for this method. Sorry. ##
~~~ MINOR STORY SPOILERS AHEAD ~~~
First, you're going to have to play through 10-20 minutes of 'The Writer' to get here, because there're no loadable checkpoints between the beginning of the DLC and here.
Just play through until you encounter the 'Alan Wake's Life Ferris Wheel' where you have to run like a hamster through a very impressively orchestrated puzzle chamber to proceed. Once you've beaten the ferris wheel, enter the elevator at the end. Note, if you don't already have it, this achievement will pop now:
The Ding! achievement in Alan Wake worth 7 pointsSpecial 2: Complete the elevator ride. NOW you should emerge into Stucky's Gas Station. Here you'll be able to pick up the HUNTING RIFLE and 2x HUNTING RIFLE AMMO from the shelves inside the store and head outside. Out here infinite taken will gradually spawn in waves of three or four and attack you. Simply empty your Hunting Rifle into your aggressors and when it goes click, allow yourself to be overwhelmed or throw yourself off the cliff (2 o'clock as you leave the hardware store)
You will reload in the store with the HUNTING RIFLE and AMMO right ahead of you yet again. Rinse and repeat.