Are privates free to select their equipment ??

Typically, no. Squad leaders or section sergeants would inspect the men to make sure they were carrying the required equipment. What went wrong in Somolia was that they had done several of this type of raid previously and each time the plan went off without a hitch. By the time of this mission the the thinking sort of developed "Well the last 3 times I didn't need NVGs, extra water, whatever" and so essential gear was left behind. It was a failure in leadership. About the only exception is when it comes to ammo. Then you take at least the prescribed load, as much extra as you want, and maybe a little more.

Ed