During FEXs, you'll have the T/E complement of weapons for a rifle platoon, i.e. a SAW and 203 per FT, and 3 PRC-119's per platoon. On the last FEX, this will also include an "attached" MMG squad (2 240Gs), so 3-man fire teams are pretty common. During MOUT training, M-16's will get sim rounds, but SAWs and G's still fire blanks.
And yes, everyone will get to fire the SAW at the Ivan (popup) targets down by the rifle range, as well as the MG's (M-240G, M-2, Mk-19) noted above and live 203 rounds at a different range (targets are rusted out tanks). The live-fire ranges also feature the "blue death" powder round for the 203, and illum at night.
And don't forget the live grenade toss and simulated AT-4 (9mm tracer round instead of a rocket).