I’ve been using a form of the ballistics xlr or the Rex reviews type of charts with my own twist on the ballistic calculations. If I’m using a ballistic computer and it goes down, I can calculate my ballistics by hand, or with a calculator. For measuring distance, and the range finder goes down, I mil my animals. I’ve measured a lot of deer over the years just for this purpose. I believe in having several backups for everything involved in making a shot. I’m really enjoying your videos!! Great content as always!!