The reason being is I did not have a complete pass through. I would worry that if shot in close range that it may expend energy to soon and have a slower kill. If the animal runs, and the bullet does not have an exit hole, good luck with a blood trail.
In a .338 win mag, where the velocity is significantly less, there is less chance of overexpansion to this extent.
If the elk or said animal was guaronteed to be more than 400 yards out, where this bullet could get down to around 2600 fps with this rifle, then I would be more comfortable.
Not enough expansion = bad, too much expansion also = bad.
Dave