RE: 40 yard shot
Antler Eater said it all.
He is 100% on the money.Deer react more to a close shot than they do to a long shot and more can go wrong with the really close shots.It becomes about skill and cofidence for the longer shots.If you are skilled and conident enough,then take the shot,if you are not,then don't.
Good light and knowing your shooting lanes is also a must.Calm animals and things of that nature are also a must.
Heck,I shot a small doe at 35 yards WALKING and put the arrow right where I squeazed the release.