I never have, but a friend of mine did that I loaded for. S&W 6", 40 yds., 158 gr. XTP, 16.2 gr. WW296. Dropped at shot with a neck shot that broke the spine. He was lucky to get that hit, but he is a super excellent shot.
It was a fast reaction shot that he didn't have time to access his primary single shot handgun.
Definitely not something I'd recommend. Bears are not bullet proof, but their muscles and bones are legendary for sucking up little bullets with poor results.