I didn't make it!
That ALL rifles killed with one shot even the bar. Your weapon would be dropped if you where hit with one smg shot or stunned by a grenade. Smgs would kill with two hits (health bar I believe but no pick ups) or one head shot. Trip wires with two grenades. It was a multiplayer mod also. I ran into it awhile back but never found it again. It was pretty darn wicked. Thanks for any help folks.
Was it the Armed rodents mod, by any chance? As it matches what your saying.