As it runs out quickly, it's heavily not recommended against any elites with lots of buffs.
Most 5★ sniper rifles don't help a lot in latest event stages due complex usage of it. Only useful till reaching 10th Story Stage.
AWSM stands for Arctic Warfare Super Magnum, which is known as sniper rifle operates with .338 Lapua Magnum. This variant is a heavy resemblance of AX308, but with different handguard and chambered in 7.62×51mm NATO or .308 Winchester instead .338 Lapua Magnum.