BDC- Bullet Drop Compensator. Yours is probably not the one designed for ML's. The one for ML's is called the Omega. Yours is like the Leupold B&C or Varmint reticle. Main difference is that their's is a single bar with windage adjustments. Nikon's is for drop only. You have to shoot your rifle to understand how to use it. Some people use the center of the circle, and some use the subtensions of the circle, when they calculate(through shooting) what range each circle or subtension is for. If you are the typical shooter who shoots a box or two every two or three years then the reticle is useless to you. If you are a shooter who shoots alot and at longer distances, it could become invaluable. It really depends on you, what type of hunting you do, and how far you shoot. I just got a 4 X 12 from SWFA for my new Ruger 10-22(actually unwrapped it while reading your post). Great scope for a good price. I should be able to hold on out to 125 yards or farther. WHO KNOWS. But I sure will shoot it to find out. Tom.
