+Terry Decker Mr. Decker, happy to hear you took some time to watch this video! Thank you for bringing this error to our attention. As you are aware, the TUBB DTR is available for a number of popular bullets. The DTR David used during filming does not match the graphics later used for this instructional video. I do not recall the specifics of Davids rifle/scope/ammo combination for this session of filming; however, the DTR (graphic) used for this illustration is for a .308, 175 gr. Sierra Match King bullet, scope 2.75 inches over bore centerline and a 100 yard zero. The fact you asked this question leaves me feeling confident that you've grasped the fundamental concepts of the TUBB DTR. I will try and link this comment to the video, to prevent any future confusion. Thank you for your time. C. Tubb