I have shot a 6.5" and own a 3 7/8". For me personally, the 3 7/8" feels more balanced, gets on target quicker and the transition from target to target is smoother. The longer sight radius is a factor with a barrel length difference of 2 5/8". With that said the 3 7/8" gun is quite accurate. Regular dry firing practice to get in sync with the revo action will overcome any sight radius issue. Also, have your S&W revo action Carmonized.