Looking at that bullet it hit something pretty hard, likely the shoulder bone/plate and it deformed the tip. Furthermore, it was likely deflected and traveling off-axis through tissue. With the tip deformed like that mushrooming wouldn't be likely, take it off-axis and it won't expand at all.

Most of the modern bullet designs will work over a wide velocity range. Some are even specially designed for very low velocities such as when used in 2" barreled .38 specials. But if the bullet gets to going sideways, it won't be able to expand as it relies on hydraulic force of tissue to cause the expansion.

Edited by BroncoGlenn (07/20/07 10:04 PM)
If you don't eat your meat you can't have any pudding. How can you have any pudding if you don't eat your meat?