RE: Margin for error. ?????
I agree Stubblejumper, there is a margin for error, with good shot placement! As you've said, there is a good margin for error with lung shots, and little or no margin for error with head and neck shots.
There are also good brush guns. Shorter barreled, with low magnification scopes, are good brush guns! There are NO "brush busters!" All calibers of bullets will be deflected by contact with brush!