When I get out and about in the woods, I carry my 4-5/8" Super Blackhawk.
Incidentally, the only documented case of a man successfully killing an Alaska grizzly in self defense with a handgun occurred last fall. A Fairbanks moose hunter and his partner were attacked by Mr. Bear. One shot from a 7- 1/2" .44 Super Blackhawk dropped the bear. The hunter put 3 more rounds in the bear when his partner stopped him because all the ammo they had left to get out of the woods was in the gun.
(This is the only documented case. Indubitably, others have been succesful in the same scenario, and decided not to put up with the hassle of reporting the incident.)