The APG is out. I have some ideas!
Grind Armor [ONE-ACTION] FEAT 1
Requirements You wield a two handed weapon.
You slam the target as hard as you can snapping bone as well as armor. Make a Strike at your current attack penalty. If this Strike hits, the target takes damage as normal and the armor the target is wearing also takes damage. Once an item’s damage reaching the broken threshold and the armor is broken, you can no longer deal damage to the armor with this feat.