Yes Big bears have been taken with the good old "06 but as with everything shot placement counts for a lot! A can of bear spray is usually on my belt if I know Grizz is around and I hunt with my 300wm. Spent two weeks hunting moose near Mackenzie BC early season in 2015, saw LOTS of bear sign and saw 1 boar and two sets of mamma and cubs on different days, nothing close to me, but at the time I was hunting with my Vanguard in 30-06 and didn't have any spray, One early morning I split up with my hunting partner and walked the edge of a cut block solo, Got that hair on the back of my neck, eyes wide open, ears straining to hear ANYTHING, sweaty palms feeling. Nothing happened.. Only time I felt really vulnerable and unprepared. 300wm has only a slight edge over the '06, but that's what I take out now. False sense of security maybe, but I feel better.