Question about noninfantry MOS in the Marine Corps?

Okay, my original MOS was an 03xx but I left for boot camp a month earlier and ended up getting stuck with a POG supply job. I enlisted because I wanted to experience life as an infantryman as crazy as it sounds. But my question is for those of you that may know what I'm talking about, how much time outside of the wire will I see? I don't want to be a FOBbit, I want to feel like I'm doing my part for the Marine Corps and actually fighting. I was told in MCT that I could volunteer for patrols and the QRF. Is this true? Also, in the other MCT training platoon, we had a combat instructor whose original MOS was Warehouse clerk but he'd had combat experience, did he volunteer also? Anything is much appreciated! Thanks!