When I attended sniper school we were using the M21 system. The scopes in those days were adequate but nothing as high tech as the scopes available today. I recently purchased a Nightforce 3.5 - 15X tactical scope and can't get over it's clarity. I am self taught in the use of Mil-dot scopes and find them to be excellent, I completely understand the math when we are talking about MOAs. This particular scope however is not in quarter minutes, half minutes or full minutes of angle adjustments. This particular scope adjusts in Mil-Rads. Can someone point me in the right direction as to where I can educate myself a little better in the use of mil-rads? The user manual that came with the scope is a little vague. Thanks I appreciate your help.