You need a fixture to hold the pistol for sight alignment (not a shooting rest). This device has a clamp and fine adjustments.
Fire at least three rounds at the target. Mark the center of the group.
Clamp the pistol in the fixture. Adjust the position to align the red dot sight on the point of aim (e.g, center).
With the pistol secured, adjust the red dot so that it is centered on the group.
Fire another 3 rounds to confirm the correct point of impact.
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