[7pointoh]

Every Marine is a riflemen. I've been a grunt and then moved over to communications. It doesn't matter what MOS you have. What matters is duty station. If you're in the Fleet Marine Force, you can get deployed. If you have orders to a base assignment, then those are not deployable units. But even that's not certain. The needs of the Marine Corps come first. You can choose your MOS but in your first enlistment, you cannot choose your Duty Station (this is for the Active Duty Side, I don't know about the Reserves).