@Safari Dave I feel like a newbie asking some of these questions, but I want to understand more of this.
When you finish a range session with a rifle, if it is 2” right, are you adjusting it to shoot zero (bullseye) or are you leaving it at 2” right and waiting for the next range session to see if the range weather condition caused the shift?
Do you normally end a range session with a goal of having the rifle right at zero?
If you have a box of ammo that groups poorly, do you record it, but still use the ammo later?
Are you generally sighting in for Max point blank range or just a little high at 100 to be at zero at 150?
I ask these questions as I’m always curious to learn new methods. I try and run all rifles at 100 yrd zero. With my rifles, when the are on the bullseye on one day, I expect them to be very close to the same the next range trip
1. If I leave the range with the rifle shooting 2" right, I just leave it until the next session. (maybe I run out of ammo, maybe the ammo wasn't doing what I expected, maybe the weather, etc. It gives me a starting point for the next time, but also tells me where to aim, just in case I have to use the rifle).
2. Typically the goal is to leave the range with the rifle sighted in. However, it might be that I overestimated the time I would have, took too many rifles, found the accuracy of the ammo lacking, etc.
3. If I have ammo that doesn't shoot well in a particular rifle, I record the fact on another spreadsheet (This spreadsheet contains rifle specific information (serial number, cost, estimated value, date acquired, where I purchased the gun, scope, rings, number of spare magazines, ammo that shoots well, ammo that doesn't, etc.)).
4. I usually shoot on a 100 yard range, but create "dope" based on published info. (I would try to zero a .30-30 @ 100 yards, I might want my .300 Magnum to be 2" high at 100 yards). When given the opportunity, I shoot the rifle at the actual desired range, then record the results.
I will use a calculator like this, to get an idea of where the approximate POI will be at distance:
Calculates the ballistic trajectory of a bullet fired from a rifle, handgun or other firearm. Produces a ballistic trajectory chart and table that shows the drop, velocity, kinetic energy, windage, and trajectory of a bullet.
shooterscalculator.com
They are never exactly right, but they sure beat just guessing.