2nd, 3rd, and 4th SBCT of 2nd Infantry Division use them. Any Stryker Brigade will use the M-777. Units designated as an Infantry Brigade Combat Team and Airborne units will use the M-119 to keep up ther "ligh-fighter" image. (Keep in mind in Afghanistan the M-777 s used universally, so you should get to use both) and Heavy Brigades will use the Paladin. The M-198m is phased out I believe on Active Duty, National Guard still has them I believe. We just tranistioned from M-198 to M-777 two years ago.