JSB 18 gr. at 720 fps, zero at 35 yards is only 0.53" high at 25 yards.... That is 0.59 MilDots.... Sighted at 35 yards the trajectory never gets above 0.7 MilDots.... At 55 yards you would be 3.6" low which is 1.8 MilDots.... If you got a 6" POI shift with the TKO my guess is that it's clipping the pellets.... Try rotating it a quater turn at a time and shoot a group each time....Bob
At 50 yards my disco will do dime size groups in a gun vice.When i take over i get 1.5 to 2 inch groups so the disco is better than me.