Perhaps the single most useful thing to learn off by heart for the Hunters and Guides…
Look up “Firearm Science” YouTube videos if you are having trouble with a concept. They do very short, very clear videos on all sorts of aspects of firearms. I am only picking out a few for you so that you can see what I mean.
Firearm Science – Internal Ballistics
Firearm Science – Bullet Trajectory
Firearm Science – Rimfire versus Centerfire