As another poster has already deduced, this is a personal rifle in a department vehicle. Modifications or changes to the rack itself is not an option, otherwise I wouldn't have posted the question I did. Everyone else, thanks for all the helpful advice instead of immediately assuming I'm a moron.
Unfortunately, it isn't a variable loop like the Santa Cruz others posted, just a solid circular loop with a single hinge. Can't find a good picture online or take a picture myself right now, but this is what the system looks like:
http://www.chiefsupply.com/images/pr...600/VEH007.jpg