Campaign: Ammunition resets on level transition?

I love the campaign for Titanfall 2, but there's something that's been bugging me. I run into a problem of getting full ammunition for a weapon (say, the EVA-8) and then when I finish the level, my ammo count is reset back to 32, the default ammo count, rather than the 120 ammunition I had beforehand. Is this a bug or a feature? I just don't know...