Mosshadow, from my experience only scouting missions allow you to keep weapons and items, though i could be wrong. The weapon you are carrying on your body and ammo seems to save from the main missions.
Ok i have a question. I am scouting right after the first mission in survival. I went to camp tempest and killed everyone there then looted everyone and everything to bring back to camp (gotta keep the camp supplied right lol) and i put it all into Zamak transport to haul back. But there is no option to enter the vehicle. So far the only vehicles i can drive that i have come across are the quads. Are enemy vehicles locked out, or only this one? Thanks.