Which position involves very limited support for the rifle?

The standing position involves very limited support for the rifle because the shooter is fully upright and relies mostly on muscle strength and balance to stabilize the firearm. In this stance, the shooter has no ground support under the rifle, making it more challenging to maintain accuracy, especially over longer distances or in windy conditions.

In contrast, other positions like kneeling, sitting, or prone allow for greater stability and support. For instance, while kneeling, the shooter can rest the rifle on their thigh; in the sitting position, there's typically more contact with the ground; and the prone position allows the shooter to lie flat, providing the most stability and contact with the ground to stabilize the firearm. Consequently, standing is the least stable of these positions, which is why it is associated with limited support for the rifle.