If the speed of sound is roughly 1100 ft/sec or 761 miles per hour.. and our bows shoot roughly 250-300ft/sec ... other varialbles..like stated above.. vital area size.. example turkey versus elk.... etc..

Factor in a living animals fight or flight response to stimulus such as sound waves from our bows firing.

The longer the shot the more time a critter has to gather/react before the arrow strikes its target.

I think no more than1.5 to 2inches of error should be considered for 30-40 yard shots on deer...sized vitals..maybe less because of distance and reaction time..

close shots.. 20yrds.. 1 inch max, theres no good reason for a well practiced bowhunter and a properly tuned flat shooting compound bow to miss by more than 1 inch at 20 yards or less...yes it allows less time for the animal to react..but still a 20 yard shot with a compound bow should be a slam dunk.

I'm going with no more than 2 inch...is acceptible for shots on live animals like elk, deerout to 40 yrds, that maybe too much on deer..

I dont know maybe I am off base here....If nothing else this post got me thinking about my own shooting..am I holding myself toahigh enoughstandard in my practicing.

For stationary target practiceI better be no more than 1 inch out to 40... ???