The true name of the AWP from Counter Strike, the AWSM (Arctic Warfare Super Magnum) is chambered in the highly powerful .338 Lapua (8.60x70mm) cartridge. This weapon is almost ungodly accurate, having been reported shooting accurately at 1500 yards and beyond.
A less powerful brother of the AWSM is the AWM (Arctic Warfare Magnum), which is chambered in .300 Winchester Magnum.
Even less powerful is the true AWP (Arctic Warfare Police), which is chambered in .308 Winchester (7.62x51mm NATO)
The civilian version of the AWP is fittingly named the AW, simply Arctic Warfare. This is chambered in .308 Win. and .243 Win.
Accuracy International also makes a version of the AW in .50 BMG (Browning Machine Gun)