Re: temperature /speed chart ?
The "Major" changes are the ones to be extra concerned about.
A change of only 10 degrees and 1000 feet elevation is not a major concern. As a matter of fact, a temperature change of 50 degrees really don't change the MOA that much in my 338/416 at 1000 yards. It is 15.5MOA to 15.9MOA at 1000 yards. 4/10ths of a MOA is only 4" at 1000 yards. Not really enough for me to miss the target/animal I am after.
Now if you program a 40 or 50 degree change the "same time" you rise in elevation from 1000 feet to 7000 or 8000 feet, now you have a major change. This is a 17" difference with both temperature changes and alltitude changes combined "in my rifle".
If the temperature and altitude is not "major", the trajectory is not effected "to an extreme".
A hand held computer is available for this if you want to carry it.
I trust my rangefinder, my rifle and my spotter for this change and take a spotter shot 100 or 200 yards away from the animal first, make my correction and then swing back on him for the kill. This procedure is done when the ranges are extreme.
Most times at only 1000 yards I go right for him the first shot.