To determine proper fitment of the DOPE Roller assembly to your Quick Detach sling swivel stud, depress the button on the opposite face of the DOPE Roller from the QD sling stud. While depressing said button, plug the DOPE Roller into the QD sling stud and rotate the device. After releasing the button, lightly tug the DOPE Roller to ensure proper fitment. If the DOPE Roller rotates freely without any resistance, remove the DOPE Roller from the QD sling stud, depress the button, and slide one of the included washers past the four ball bearings (two washers may be required for QD mounts with loose tolerances).
The DOPE Roller should lock firmly into place to the QD stud and not exhibit excessive wobble or looseness when rotated. There should be a slight resistance when it is turned by hand. If the DOPE Roller does not rotate when applying firm pressure, verify that your QD mount is indeed a 360 degree design (not multi-positional). Multi-positional designs will require the button to be depressed in order for the DOPE Roller to rotate. If your QD stud still exhibits a significant amount of wobble, it likely features fairly loose tolerances. Give us a call, or place an order from McMaster-Carr for an additional washer, and then you’ll be good to go.
Once proper fitment has been achieved, determine your correct windage and elevation holdovers at the distances you intend to reference. Record your DOPE (Data On Previous Engagement) on a 1” x 3” adhesive address label of your choosing. The following links will provide instructions on how to determine your DOPE with a Kestrel Weather Meter, various Ballistic Apps, or through a basic field exercise.