This is our other style keychain. A little nicer with a steel pin coming out of the primer hole. This pin cannot be removed. Bullet key chains using deactivated rounds of the caliber of your choice. Please note that casings can vary on ammo brand or look. 50 BMG is very large at 5 1/2 inches long and 3/4" in diameter. However, for some reason, it is very popular with our customers and is one of our best sellers.