The VAST majority of military sniper rifles are .308, and have been for well over 20 years. The majority of sniper rifles currently being built by the MTUs are also .308. There are some applications for the 50 cal, and they are currently being used in Iraq, as they were when we were inSomalia. Some civilian police tactical units use 300 mags, .223, and a few other calibers, but they are in the minority.Most still use the .308.