I picked up a K31 a couple of months ago. I finally got a chance to take it to the range. I replaced the rear sight with a scope mount and am using a Bushnell 2x6 pistol scope on it. I used the NOE 30-165 xcb, Lyman 311041, and Lyman 311299 all were 5 shot groups at 50 yards using 16grains of 2400. The wind was rocking the target stand and that may have contributed to the vertical stringing for the 311041 and 311299.