I have shot a fairly decent brown bear last year (8.5 feet), and can tell you that you should never rely on body shots to stop a bear, forget the 'light rifle', shoot at the head with a semi-auto in 10mm AUTO, you simply have more ammo and speed to make up for misses. I my case, I pumped 4 shots from my .404 Jeffrey into the bear's chest cavity at distances from 10 to 60 yards. Those were very stiff handloads, by the way, similar to full-house .416 Rigby loads. Less effective then I had expected ... :

First hit made him rise to his full 8.5 ft, with a big roar ... then he came at me. Only the second shot at 10 yards distance made him run away, as he clearly did not like what he was being served. I hit him a third and forth time at about 60 yards when he tried to pass my position sideways. At the position of the forth shot, I later found his lungs all over the place - still didn't impress him, he kept running for another 70 yards until he dropped (and was still not dead!!). The bear had softball size exit holes from my African caliber, and all 4 shots hit the chest cavity, yet it was a close call. There are bears that will fall fast, but on occasion, they can prove very tough. I own a .470 NE now, and spend most practice time with off-hand head-shots at 50 yards

.

Hence, as a backup, the handgun for the headshot is the only option, whereby I would actually prefer pepper spray: Some game department has done stats on the effectiveness of guns versus pepper spray in stopping charges: The pepper spray won by 75 % versus 30 % for the guns (in turning a charge).