That would depend on what you are useing .... Mechanical or fixed blade ....I have a friend that has been shooting 50# draw weightnd has taken Bull Moose but he does not use mechanical broadheads... He is currently using Thunderheards....He sadhed nt ae anything over 40 yards... Hope this helps...
Good Luck Hunting .....
If you want to see some low KE numbers, you should ask this in the trad forum. My last bull was shot with 64ft. pounds I believe. My next will be around 84.