A year or so ago Cabelas had a sale on Nikon scopes, so on a whim I used some of my Cabelas points and bought one of these scopes. I mounted it on a Rem 700 stainless in 7mm Rem mag, which is my backup rifle for hunting in foul weather. It's basically been sitting in my safe until last week when I thought I would see how the BDC system worked.
My hunting bullet in that rifle is the 160 grain Accubond in front of H4831SC powder. This load has worked well for me in hunts in Montana, South Africa, and Canada.
So I started off setting the crosshairs to zero at 100 yards. Then I put the first BDC circle on the 200 yard steel gong, and rang it. I then put the second circle on the 300 yard gong and rang it. Then I put the third circle on the 430 yard gong and also rang it.
My primary hunting rifle is my .300 Weatherby, and I have memorized the bullet drop at 50 yard increments out to 500 yards, and I regularly ring any of those gongs shooting prone and estimating the hold over at each distance. (Actually, if I just want to ring the gongs, the only one that I have to hold over with the .300 Bee is the 430 yard gong. The other gongs I only hold under or over 1-3" if I want to hit the center of the gong.) The BDC circles take the holdover estimating out of the shot (for just ringing the gongs).
This wasn't a precise test as the gongs are 16" in diameter, but it was fun to just center each gong in the appropriate BDC circle, shoot, and ring the gong.
I have Leupold scopes on several of my other rifles, and another thing that I liked about the Nikon was that the magnification ring has a tab on it and it is much easier to turn than the Leupold rings are.