Okay, back story first: I work at a Ford dealership, and there's an Air Force base right down the road. We do the warranty work for all the Ford vehicles on base. They have a whole fleet of vehicles called "BearCats" that are APCs built with Ford chassis and drivetrains, so we work on them fairly often. These vehicles have turret mounts on top to mount machine guns (the guns are always removed when in the shop). We had a BearCat in the other day, and in the turret were dozen of spent shell casings, but no one in the shop has any clue what they are. I'm hoping someone here can help us out. I've paired the casing with a 5.56 on the left and a .270 on the right. My thinking is short action, but what? On the base of the casing there is an "L", a "C" a "5" and an "8", but no indication of caliber. Any thoughts?