A couple of years ago on a cow elk hunt with some friends, I tested penetration of a Montana Bullet Works 200 grain hard cast lead handload, Underwood 200 grain lead flat nose hard cast, and Underwood 200 grain full metal jacket bullets on cow elk skulls. My handload and the Underwood lead flat nose hard cast completely penetrated two large fresh cow elk skulls. Those bullets, 2 shots each, were not recovered. The Underwood full metal case rounds (2 shots) broke up in the first skull. Recovered pieces of jacket and bullet told me the jacket was made of very thin, brittle material. The lead also broke up and seemed brittle as well. The FMC round was accurate and functioned fine in my G20, but it was not a penetrator.
