The cache will be easy to find, but you must solve the onsite puzzle inside the ammo can to retrieve the logbook. Please follow the instructions inside the ammo can afterwards to put everything back together properly.
There is no need to use brute force to pull the puzzle pieces apart! Once the puzzle has been correctly solved, the pieces will slide apart!
Centripetal force: The force that pulls a rotating object towards the center of rotation and keeps the object from "flying out".
Centrifugal force: The apparent outward force that pushes a rotating object away from the center of rotation.
Observed from a non-inertial reference frame, centrifugal force is known as a fictitious force. But it may just help you solve this puzzle anyway.