As most folks here already know, I'm old, lazy and suffer from CRS. To overcome some of the problem, I've come up with a few things to make life simpler.
First I started using nine shot butt stock cartridge holders. I cut a slit in the bottom and place the hole over the swivel stud which keeps it from squirming around. Besides holding ammo, it serves another purpose. All my Handis are sighted in for the longest range load that maintains accuracy. The cartridge holders are filled with that load. I can't remember all of those ballistics for each rifle, so on a 3 x 5 card, I mark the load, velocity, sight-in range and the rise and drop increments to that range and beyond and tuck it under the cartridge holder. Before hunting or shooting with a particular rifle, I pull out the card and take a refresher course. Now I know what I've got in my hands. If I change a load, I change the card.
Pete