Armor Regen on striker

Agents, Does anyone know if it’s possible to get armor regen on striker gear without having to calibrate it? I want to use my calibration to change the core to armor which I know never comes on striker gear. But I’d really like my secondary attribute to be armor regen. I have spent hours farming striker on countdown and drained my resources at the crafting table to get one. I have seen a single piece of striker gear ever come with Regen. Am I an idiot wasting my time and resources or am I doing something wrong?