If you want to get good at sniping, then all you have to do if follow this tip.

Go to any map on forge and put it so you have infinite grenades and infinite ammo and start the game. Wait until your grenades replenish and toss a grenade up in the air and try to shoot it with the sniper rifle before it hits the ground. In no time you will be owning your friends with the sniper rifle without even zooming in.

Another way to get good but a bit more deadly is to have one of your friends fire rockets at you and you try to blow them up before they hit you, it takes two hits with the rifle to destroy a rocket and one hit to blow up a grenade.