Scout snipers lie in one spot and count trucks, gather intel, surveil targets and maybe for days on end, whizzing and pooing themselves where they lie sometimes. It's not a glamourous job all the time. Rarely, they may engage a target depending on the mission. You are not going to be whacking guys at 800 meters as a general rule of thumb. It's a job you have to have an incredible amount of patience to do as it is a job of very little action besides movement to a target, gathering info and movement from a target area.
Generally you have to make your bones on active duty for at least a few years first to get considered for a STA platoon. The sniper indoc, which is a few days long, is the tryout It consists of a Marine Corps PFT, land nav, PT, night land nav, PT, swim for time, and our unit did a 25 mile hump with full rucks which the STA platoon attached it's wannabe to after their three days of torment as the finisher.
The army direct to SF really isn't unless you meet all the requirements of the contract which can take years to do to actually make it to the tryout. No one goes direct.