Truing your ballistic data is something everybody should be doing regardless of skill or experience level. The practice of truing your ballistic data is a fundamental necessity if you want to have accurate adjustments and drop charts for long distance shooting. What we are talking about is taking the data that is output by a ballistic solver or computer and tweaking it to match what we see in real life. You should never just generate a drop chart and assume it will be correct. There are too many variables in play here. You need to generate a drop chart and then check its accuracy with live fire. Then you need to adjust the chart to match what you are seeing in the real world.