I have the 6500 2.5x16 for a year and so far am very happy with it.I mounted the 4200 2.5x10 on a friends Tikka and is also very nice.I reccomend the 6500 because of the adjustable parallax and the generous magnification range.Both scopes are the same length and 1.3oz differance in wieght.So if money is not a factor the 6500 is it shop around and u will find it under $600.