Why are bullet drop and trajectory in two different categories? Aren't they basically the same thing? Trajectory is the map or line that describes how far you bullet drops over distance right? So why the two separate categories?

mburu

I think it is important to distinguish bullet drop from bullet trajectory.

Bullet drop simply deals with gravity and the bullets velocity. Bullet trajectory deals with how a bullet travels vertically (up and down) as it moves down range. A shooter can do a lot with his shooting rig if he understands the trajectory of his cartridge. One example (That I think is ridiculous) is maximum point blank range. Another example (That I think is very useful) is finding the true zero or a derivative of the true zero for your rifle. These use trajectory to help the shooter know how to deal with the bullet drop and hit his target at multiple distances without having to spend a lot of time adjusting.