The L115A3 is the sniper rifle in Warmerise. It is one shot to kill for a headshot. It zooms extremely far, making it necessary to find your target out of scope, line up your crosshairs near the target, and then zoom in. Searching for targets in the scope is very ineffective.
To be a good sniper, practice is the key! At first, aim for still objects, then slowly progress to long range objects then to moving things.
In the scope, know the points to shoot walkers or sprinters. Make sure your crosshair/red-dot is always in front of the person you are shooting, it will always get your shot in. And again, know the points on your scope to shoot sprinters and walkers!
Predict the enemy's path. It may be hard, but lets say he spent five seconds wallking a certain way, at this point, aim in another direction he can possibly turn at, since he won't be going in that direction for that he was going too. If he exceeds the limit, he is most likely heading for an objective. Check to make sure that he really is heading for something in that direction. Check for buildings, jeeps, or enemies nearby to strengthen your hypothesis, then shoot.
Always go for long range shots, as people can not see you and they are much easier to shoot, mainly since your enemy will never run out of your scope.
In medium range, be sure to always move your scope along with the target so you can never loose them in sight.
Quicksoping requires much time and practice. Start by setting your goal at two seconds at scope and make a kill. Make sure you know steps 2 and 4, as these are extremely critical to a beginner. Once you reach the one second mark, these two skills will be used more less, but step 4 will be more important than step two. Soon, with enough practice, you can just aim your cross hair at the enemy and be able to quickscope like a pro!