Average person is 165lb and a S&W40 has 400lb of KO power
Average bear is going to be 500-600lbs and a 44mag has 1000LB of KO power.

Yes a 40 sw will bring it down but it is like a 22lr on a deer unless you hit it in the head or spin you better keep firing. If my life is on the line and I am putting small holes in it I might die and that is a risk I am not willing to take and i bet your would not if your life or say your KIDS life was on the line. On a large animal you need to tear up them interal organs as fast and as much as you can.

The exstra 2-5lbs of iron is worth its weight in gold time in and time out.