Originally Posted by SATYATEX
I found 7 so far and wasted 2 hrs with searching for the last one with no luck... even couldn't find the 8th keyring.
Did you get the one on the crate underneath the staircase in the shooting range? The key is hanging off the crate directly to the right of it if you're coming in from the kitchen.
That one gave me the most trouble since it blends so well into the darkness and environment.