At TBS you'll be issued a wish-list for auxiliary weapons. They include the M203, M27, and M240.
The M203 is a launcher that attaches to you M16 and you'll carry it everywhere you go, maybe even on hikes. You may be able to fire it once or twice in the field.
The M27 is an amazing weapon with an amazing rapid fire. You'll be issued an M16, but on select days, you'll head over to the armory and swap out for the M27. You'll being this to the field but you won't carry this on hikes.
The M240 is a medium machine gun that requires two operators, the gunner and A-gunner. On select days, you'll head over to the armory and check this weapon out. I believe you check out this weapon IN ADDITION to your M16. I'll get back to you on this. The M240 includes the weapon, the posts, and the bag to carry the posts. You'll bring this to the field but you won't carry it on hikes.
When you hold a billet, it is very important to know which weapons are in the BOQ (Basic Officer Quarters) and which are in the armory. In Garrison, the M203s will be in the lockers. If you have duty, make sure to inspect lockers extra hard, as they can be hidden or detached from the weapon. The M27s and M240s will be in the armory, but the bags may be in BOQ. Be accurate!
In the field, your M16 count will be lower if people have swapped out for M27s. Sometimes, weapons will be under repair, so don't just copy the numbers from the day before. Actually count.
Everyone will get the opportunity to fire all these weapons, but primarily, whoever is assigned these weapons in the beginning will have these weapons the whole time. When writing you orders, make the roster so that these weapons are split strategically between fire teams/squads.
If you want to go infantry, I recommend signing up for an auxiliary weapon, especially the M27 and M240!