With black bears it's all about shot placement. I've killed three black bears now and had a friend kill two. Average recovery was 35 yards. All double lung shots, all pass throughs like a hot knife through butter and all from bows between 50 lb Bear Grizzly to a 60 lb Super Shrew (my last bear with this and Easton Axis at 525 grains using 3 blade Razorcap). Other than my last bear with a Razorcap, the rest were shot with Zwickey Delta 2 blade heads on 500-550 grain cedar arrows.
Heavy arrows and Snuffers are fine, but I'd worry more about accuracy with bears. A poorly hit bear will go forever
http://www.shrewbows.com/raylyonbear2008.html (The reference to once in 30 year bear means I won't draw a tag for that unit for another 30 years due to preference points needed.)