Here's the deal with the BDC...
The BDC is a series of small circles below the crosshair. Depending on how flat the cartridge shoots, you can sight in the crosshairs for 100yds or 200yds. Lets say you sight it in at 100yds... Go out to 200yds and using the crosshairs shoot at the bullseye. Mark the hole with something highly visible, and see where it appears in your scope w/ the crosshairs still on the bullseye. On the BDC, you can use where the top, bottom, or center of the circle on the verticle line. Lets say it doesn't match anything. Well remember, Nikon's reticles are on the first focal plane, so adjusting the magnification doesn't change the reticle. This means, as you reduce the magnification, the reticle will APPEAR to change in relation to the target. In simplier terms, in order to use the BDC with your rifle, it might only work when the scope is set at 4X. On top of that you will probably have to remember something like, "Scope at 4X, crosshairs=100yds, top of first circle=150yds, bottom of first circle=200yds, bottom of second circle=250yds, bottom of third circle=300yds., etc.
As you can tell, it seems to be a bit labor intensive for me! A standard 3x9 Buckmaster sells for $200.00 so it isn't a bad deal. Instead of wasting your time on trying to figure out the BDC, I would suggest simply sighting in your scope for your cartridge's Maximum Point Blank Range.
Jim
