Dude, If you shoot a.223 cal rifle,any kind of rifle, you owe it to youself to check out this scope and mount. Nikon's M-223 3-12x42SF with a Rapid Action Turret. This thing is incredible. I have one on my AR .223 and have had a ball with it. It will make you a better shot and save you $ on ammo. I am getting another one for my Heavy Barr. Savage too!
Check out this web site as well. I found it when I was reading about the M-223 scope by Nikon.
Nikon Spot On™ Ballistic Match Technology Program