I've been trying to establish a pattern but it seems to be happening randomly. Often there are no engineers around so the only way to get ammo is to run to an equipment terminal and click resupply. Sometimes when I get there my default class has switched from Max usually to light assault. Most of the time it's set at Max where I left it and getting ammo is quick... click resupply. Unfortunately when I least expect it after resupplying several times I don't notice that it has switched to light assault and I'm stuck waiting for my timer on my max to run down while the sky outside is full of aircraft....then the process starts all over again. I can't quite put my finger on when this happens or why.