I think you raise a good point about the effective penetration at 80 yards. For now I only deer hunt and 30 yards is about as far as I want to shoot. I think before I started shooting an elk at 80 yards I would want to know how much energy I am losing at that range. I think I would set up fresh 3D or foam target and compare the difference in penetration at 20 / 40 / 80 yards. Not too sure if it is any harder to penetrate an elk versus a deer given it is in the boiler room?