Which action is NOT part of the elevation adjustment for the M240 front sight assembly?

The correct choice reflects an important aspect of the elevation adjustment process for the M240 front sight assembly. When adjusting the front sight, it is essential to note that the sight blade can be turned both clockwise and counterclockwise to achieve the desired elevation settings. Confined to only turning the sight blade clockwise would not accommodate corrections that may be necessary based on the situation or existing sight alignment.

Understanding the mechanics of how the sight assembly works shows that the front sight's blade needs flexibility in adjustment to ensure accurate elevation based on the target distance and any ballistic considerations. The other actions listed are indeed part of the necessary steps for adjustments. For instance, applying lubricant helps ensure smooth operations, lifting the retaining strap allows for the adjustment to be made without the strap getting in the way, and lowering the retaining strap secures the adjustment once completed.