Ballistics 101: What is caliber, exactly?

Author: TFB Staff
This article originally appeared on The Firearm Blog. “Caliber.” It can mean a lot of different things, but when we use it, what does it really mean, and what’s its significance? Today I begin a series of posts on basic ballistics, and the theory behind them, both external (how a bullet flies through the air) and terminal (how a bullet penetrates a target). For the first few installments …
Source: Police Updates
Ballistics 101: What is caliber, exactly?