I have been attacked by a large grizzly(really it was after my dog), & i killed it nicely with my 30-30. The bear was in full blast attack mode & my first shot through its heart was not even noticed, although it would have obviously died while mauling us. My second shot was in its spine, & stopped the attack. I really dont believe that any larger gun would have done better. I usually carry my ultralight ruger in 30-06, but this is more for the scope mounting platform than because of power as i feel the 30-30 is plenty for any game in canada. If it is a dangerous situation, only a brain or spine shot will end it quickly. Any bullet, no matter how powerful, shot through the guts is not going to stop anything right away. Also as a Yukon Ranger I am totally surprised by the comments about the Lee Enfield being unreliable, in 15 years of group shooting the only failures were caused by new shooters not stacking the ammo properly. Brian.