Nice shot. If you are practicing it all the timeand hitting then you are good to go on the shot.
The bullet flight time was brought up, but that isn't the whole delay. How long does it take most of you to physically pull the trigger? On the inexpensive shotguns and muzzle loaders the triggers often have a long pull. How long process the decision to shoot and send the signal to your finger?
How long is it between when you consciously decide to fire and when that bullet hits the target, even with a shotgun at 40 yards?
How many of you, or more relevant general hunters, are going to take the shot from the moment you exhale? There might be 3-5 seconds in between the moment they exhale and when the bullet hits the deer.
I saw a guy shoot a doe with a scoped shotgun. Not a hunter. Shot a few slugs a year. He tracked the doe fine, then when he decided to shoot he stopped tracking. He didn't know how to shoot with the barrel moving b/c he had only practiced from a static position. Deer did not stop walking. Shot the deer in the hip. Cussed, pumped, and put a second shot in the kill zone without any issue at all. Then said something about not leading enough. The deer was walking and the shot was 35 yards.
My guess is that for some hunters the flight time is absolutely insignificant.