Hitting a target at 45-50-75-100 yards is responsible preparation for humane hunting. Taking shots at animals at that 50 yard range is border line irresponsible in my opinion. But I stress, in MY opinion. To each their own, but I hunt only by the grace of God and His majestic creatures, not...
You DO NOT need anything near 70# pull to hunt big deer. If anyone tells you that, they are trying to invoke their ego on you. Don't fall for it.
60# max pull with 80% let-off will be perfect for your situation. You can even go down to 50# (depending on what's legal where you hunt) and still...