The sniper rifle is a bolt-action rifle which is often utilized by police officers in Japan and the States-you may also find a special silenced version of the rifle in the Cuban civil war mission with Carlos after taking the Capital building from the rebels supported by The 7.
As a weapon goes it is a fine gun, featuring high damage and accuracy. The fact team-mates replenish your ammo,you can kill off droves of enemies from afar.
It is not a featured weapon in the multiplayer maps-unfortunetly.