RE: 5.56/223 for elk/moose(don't flame me yet!)
The problem with the FMJs is they have a tendency to tumble as soon as they hit something.
If it wasn't 20 some below right now I have an old Ford 360 engine sitting in the junk pile. I could go shoot it from whatever distance and give the results. Wouldn't have a grill, radiator, fenders, bumper, inner fenders, etc to slow it down.