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AR15.COM
5/4/2025 5:46:37 PM EDT
[Last Edit: AASG][Edited]
What does the knob on the left do? It looks like it has yardage listed on it. Is it like an adjustable objective?
5/4/2025 6:53:42 PM EDT
[#1]
Parallax adjustment
9/12/2025 12:11:43 PM EDT
[#2]
Hi there. That knob is your Parallax Adjustment.
Parallax adjustment on a scope aligns the reticle's focal plane with the target's focal plane, eliminating perceived reticle movement when the shooter shifts their head position. By turning the adjustment knob, the shooter achieves a clear image and a zero-parallax condition where the reticle remains stationary on the target, ensuring greater shooting accuracy, especially at longer distances. An example of this is while shooting at 100yds the shooter would adjust the parallax dial to reflect the yardage they are shooting. 100yds in this instance. The same is true to any other range they wish to shoot. You simply match the yardage you are shooting with the yardage on the parallax dial.

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