Re: Sierra Ballistics Program
The best thing you can do is test the charts. No program will have perfect results at long range. Bullets have different BC's depending on the gun they come out of and the software certainly can't predict that. Many other factors come to mind, but, if you make a chart, test it several times for the longer ranges so you are familiar with it. Then I adjust the BC numbers in the software to have the chart match my guns/bullets performance.
FWIW, I do use the Sierra Infinity, and still use the Sierra BALTEC Dos Version from long, long ago.
If you have something that you disassemble and reassemble enough times, sooner or later, you'll have two!