Sniper certification is so that you can shoot at higher velocities than the aeg's or gbb's on the field SAFELY. There is a MED (minimum engagement distance) that needs to be adhered to when shooting at the higher velocities to ensure safety.
Clinics are held several times a year, and train you in recognizing what engagement distances are, among other necessary airsoft sniping information.
I suggest getting yourself age verified so you have access to the threads where this information is listed.
The Tier One Tactical Operator
Tippmann Arms M4A1
KWA USP .45, KJW P226, KJW hi-cappa