>>63814410 (OP)HEAT/EFP penetration scales exponentially with caliber, below 50mm you're looking at like 1.5x best case which makes AP/sabots generally superior for both penetration and price except recoil-limited use cases like 40mm HEDP. ~26mm/0deg RHA from a 12ga won't harm anything meaningful in a trench, but there's a small chance we see it temporarily serve as an expedient solution to mass deployment of infantry-like/tankette combat robots.
>>63814823It won't, because ceramic is the primary component of composite armor arrays which were specifically adopted to defeat HEAT shells.