What is a BDC reticle scope?

A BDC reticle scope has a Bullet-Drop Compensator on the cross-hairs, featuring four small circles beneath the center on the vertical line, corresponding to point-of-impact at distances greater than a 100-yard sight-in. This allows the shooter to accurately compensate for bullet-drop over longer distances without changing scope elevation.

The Bullet-Drop Compensator reticle was first developed by Nikon and patented in 2008, but other multiple-point hold-over reticles have existed since the first World War. The first publicly available (and still the most common) is the mil-dot reticle based on the milliradian unit of measurement. One milliradian minute of angle represents approximately 1 yard at 1000 yards or 1 foot at 1000 feet. Armed with ballistic trajectory information and target distance, a shooter can use an arithmetical calculation and the mil-dots on a scope to compensate for bullet-drop.

The patented BDC reticle takes this concept one step further, and replaces numerous mil-dots with four specific circles, calculated to accurately represent anticipated bullet-drop over known distances, thus removing the need for the shooter to either make calculations or adjust the scope turrets. The circles on the BDC reticle represent anticipated bullet-drop over 200, 300, 400 and 500 yards for standard centerfire ammunition, and 300, 400, 500 and 600 yards for magnum centerfire rounds.