Unless your current zeroed scope is near the middle of the reticle adjustment ranges and you do not think you will be making major adjustiments during shooting, the Stoney Point target knobs are not worth it, IMO.
The knobs have a limited amount of adjustments by themselves. How they work is that the inside portion of the knob is fitted into the slots of the scope's adjustment screws. It basically extends the scope's internal (under the caps) reticle adjustment screws to the outside knob. Unfortunately, the knobs have a limited anount of travel. If you go beyonds the knob's travel, they will come out of the scope slots (moving the reticle away from the knob) and become useless as they are no longer attached and you have to remove the assembly to get it back in or they will stop as normal (moving toward the knob). In either case, they will not allow your to use the scope's full range of reticle adjustment distance.
In the one time I used the product on a Leupold M8, the elevation knob came out of engagement as I needed to move the reticle more than the knob can provide and when I tried to go the other way enough pressure on the scope's screw was applied to move it slightly but the knob was still not seated in the slot. This bound up the knob to the point where it was impossible to remove by hand I had to wrap the turret up with rubberband to get a better purchase and grip to get the thing off.
Oh, welcome.
