U.S. Paratroopers with the 173rd Airborne Brigade train with various weapons during Exercise Rock Proof V at Postonja, Slovenia. Weapons systems included.brUS soldiers from the 173rd Airborne Brigade fire support team doing a conjoint fire support exercise with the Slovenian armys in Slovenia. On this video you can .brU.S. paratroopers from the 173rd Airborne Brigade (Sky Soldiers) engage targets with M2 machine gun, M240 machine gun, M4 carbine, M320 grenade .brSlovenian army soldiers conduct a live-fire exercise with FM MAG machine gun as part of Exercise Rock Proof V at Pocek Range in Postonja, Slovenia, Oct. 15, .