AFK MethodIf you have a rubberband or piece of tape, you can AFK grind this achievement. Before beginning turn off Vibration in the controller settings. Then from the Main Menu go to:
Single Player > Compound > 450 (whichever you would prefer, this is what I picked) > Start
From the starting point, follow my video to see where exactly to go:
Sorry, this Game Clip has been removed
When it seems to matchup the same with where you spawn as my video, simply rubberband/tape RT and go do whatever for around 3-4 hours max. When you come back it should be unlocked.
Happy Hunting