I have killed a couple of deer at right around 40 yards and it was in my first few years of bowhunting.While my shooting has gotten progresively better,my shot selection distance continues to shrink.So much depends upon the demeanor of the animal.A lot can happen in 40 plus yards,that deer takes a step and your in it's gut's,it wheels to chase a doe,your in it's ham etc..
I also practice all the while at longer distances,50 and 60 yards,and am very comfortable at those distances on a stationary object.Now when hunting I do my darndest to keep it within 30 yards,A better hunter will take more game than a better shot,one of my hunting mentors used to drill me with those words all the time.I think it was because he couldn't out shoot me.He has taken some awfully big deer though.