First, I'd need to know EXACTLY what the range was, then, would need to know where the bullet would strike below the crosshairs at that distance and what the wind velocity/direction would do to that particular bullet weight/BC/muzzle velocity. Next, I'd need a stable, sitting position, preferably with a solid rest.
The deer must be nearly motionless and would have to be 90* angle to the shot, which would allow a high shoulder/lung hit and the most forgiving angle of the shot.
Next, I'd have to be comfortable, hands warm and my vision through the scope clear and unobstructed.
Next, I'd think about whether I wanted to shoot that deer and whether I had a good means of getting it out to the meat cutter. For instance...if there was a deep canyon between us...no shot.
My .270 Remington will out-shoot most .308 hunting rifles. It shoots 1/2 MOA and I know how much to raise the crosshairs to make a 500 yard shot. The 140 grain Accubond bullets would do the job very well at that distance.
All things being a go, I still may not shoot, because I really don't like venison.