What is the US Army's training rifle?

Answer 1

Depends on what your context is. When you're assigned to your unit, and you go to the field, the rifle you train with is the same one you'll be carrying into battle (unless you're in a Reserve unit which still fields the M16A1, in which case, you'll probably receive a different weapon when you get called up for deployment). When you go through Basic Training/One Station Unit Training, you'll likely be issued an M16... when I went in 98, we had M16A2s, although there is a chance now that M16A4s and perhaps even M4s will be present, as well. ROTC cadets usually qualify with weapons drawn from a Reserve unit in their region, which will typically be either M16A1s or M16A2, while JROTC (high school) cadets may do their marksmanship training with either a single shot pellet rifle or rimfire .22 rifle. And, for the bayonet assault course, there's the "rubber ducks" - rubber replicas of the M16 rifle, which have real barrels to which a bayonet can be fixed.