When I started hunting we zeroed our rifles at 75 yards. That was the distance to the targets from the mound which was just in front of the range hut at the North Auckland range. The range hut was behind the hut used by the air rifle shooters at this moment. All of the shooting was four position format with the addition of a snap target, at the front silhouette of a deer, and at the running deer target. This was powered by a petrol motor and crossed the gap in about 6 seconds. The 75 yard zero worked perfectly well. The prevailing attitude at the club was that shots at game were taken between 30 and 70 yards.
Most of the club members hunted the Urewera, the Kaimanawas or the King Country and the advice on sighting in worked for these areas. The first time I recall shooting at a longer distance was when we set the targets at the present butts and shot from 200yards. My memory is that of all the shots fired by the participants that day there were only 19 strikes on target. A common comment was who would bother shooting that far away, anyway. The prospect of holding the nationals encouraged competitive club members to practice at that range. I recall being surprised at how much I had to adjust the elevation on my 308.
As we were mainly close range bush hunting I think the 75 zero was used a lot. My own hunting grounds got more varied. River beds on the West Coast; alpine tussocklands along the Alps; open tussock in the army training grounds at Waiouru and in the Kaimanawas gave opportunities at much longer ranges. I used a system that I had read about which advocated sighting the rifle in at the longest range which would mean that the bullet was not more than four inches high at midrange and then find out the distance at which it landed four inches low. Then just hold in the middle and you would be good out to 230 to 300 yards. I used this system enough to know I didn’t like it. I found that there was too much of a tendency to get excited and put one over the top of a deer at the middle ranges.
On one job I tried a 300 zero then held on the belly line at normal ranges. Didn’t like that either. Good at 300 but an absolute pain at closer ranges. A head shot or a bit of the top of a shoulder was difficult. Then there was the problem of when you changed rifles you would have to learn a new set of strikes.
I’ve settled on a much simpler system. I zero all of my regular hunting rifles at 200. This distance is often available at the club and you can establish a good zero. One thing to watch out for is wind drift at this range. Choose a day when there is little to no wind to finalise your windage adjustment.
For most of my shots I can forget about holding underneath at normal ranges. Very occasionally when trying for a headshot at mid range I will make sure that there is a good amount of skull visible at the top crosshair. When I judge the range to be definitely much more than 200 and probably around 300 I will hold the cross wire at the top of the shoulder. When the range is even further than that, maybe 400, and I cannot get closer, I will hold a foot clear of the wither. Complicating these long attempts is that the shot may be at a significant up or down angle. It’s surprising how far an animal may be in steep country and you must still hold on the belly line. I go out of my way not to take these shots unless there is no option.
Most target ranges are on essentially flat ground so the opportunity to practise the hold under is limited.
I’ve found this system to be very usable in the field. You don’t have to dick around measuring range, adjusting sights, estimating wind velocity, coriolis effect, elevation, barometric pressure, ambient humidity and many more factors which can affect bullet strike. Just go ahead and shoot it. If it’s too far or blowing too hard, don’t shoot. That works for me!