Injuries to the hip are breathtakingly painful. A bullet to the hip will shatter bone and immobilize.
Breathtakingly painful? I thought gut shots were supposed to be breathtakingly painful.
Unless you are using a centerfire rifle or shotgun slugs, don't count on shattering the pelvis. Even then, if you hit the blade of the largest bone, the ilium, you can get a round that simply passes through with no structural failure or even breaks off a chunk of the blade, but this likely won't result in structural collapse. Keep in mind that the iliac blade provides a lot of lower abdominal cavity support for soft tissue. If you want real structural insult, you need to impact at the acetabulum (where the femoral head articulates in the socket with the ilium, ischium, and pubis) or hit the pubic symphysis. Note that the pubic symphysis (very small target) and ischium (the bones you sit on[left and right]) are located very low down on the abdomen.
It is a myth that impacting the pelvis with a handgun shot will break the pelvis and drop the person that is often further glorified by saying the pelvis will collapse or will shatter. People shot in the pelvis may go down, err, drop, but then again I have seen footage of people shot in the thigh (no bone involvement) drop, gut, chest, shoulder, etc., all places that didn't have load bearing collapse.
While not an exact analogy, experienced hunters faced with a charging bear will try to "dismantle" the mobility of the bear before trying to kill it.
More likely, they are doing their best to stop it any way possible and often bears get stopped without being killed and have to be finished off.
Of course, when it comes to a "charging bear," the best target presented is the shoulder as there are two to choose from and offer the dual possibilities of giving you the best chance for penetration of the body and the possibility of breaking the shoulder girdle. The head is a big target between the shoulders, but with a strong, sloped skull, necessary penetration into the brain may not occur and the head actually protects much of the vital organs behind it.
So it isn't so much that they are dismantling the the mobility of the bear as much as making the most optimal shot available on a charging bear.