Unless your regular hunting terrain involves shots over 300yds, there's really no pressing need to use a chrono. Same applies for worrying about ES/SD, irrelevant at that distance. I tend to agree with Micky Duck's approach. I zero std hunting rifles at 200yds and then would check the drop at 300. My LR rig is a different story.
The main item to get first is a rangefinder.
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