RE: Should I get a 50-60# or 60-70#
Shoot whatever poundage you can comfortably pull when in a hunting situation and comfortably hold without ANY strain.This includes heavy clothing and COLD weather.
Usually a drop in poundage is preferrable in the winter over what you are comfortable with in the summmer and as you get older,your shoulders will thank you for not over stressing them over the years.
I have shot too many 3-d tourneys with older gentlemen that can barely pull 50# anymore due to shooting heavy poundage bows for years.They will tell you shoot on the lower end of your comfort range rather than the upper end.
I shoot 58# and have no problems with passthroughs on deer size game and really doubt I would have problems on elk.