The BRC-6 operates by firing a tungsten-composite slug at subsonic velocity while simultaneously emitting a tightly coupled acoustic resonance wave tuned to the slug's terminal frequency. On impact, the slug does not need to penetrate hardened materials — the resonance wave propagates through the target structure milliseconds before contact, creating microscopic fracture networks that cause the slug to behave as though it struck compromised material regardless of surface hardness. Against unarmored targets, the effect is catastrophically overpenetrative; against armored opponents, it renders hard-plate inserts effectively useless.

What distinguishes the Kettledrum from conventional anti-armor firearms is its complete lack of exotic propellant requirements. It uses a standard compressed-gas cycling system and commercially available tungsten slugs, meaning it is logistically unremarkable in a supply chain sense — a deliberate design choice by Arcturus Defense Solutions, who engineered it for covert military advisory units that needed deniable anti-materiel capability. The resonance emitter is integrated into the barrel shroud and draws from a small onboard power cell rated for approximately 200 sustained discharges before replacement.

In the field, operators describe a distinctive low 'thrum' preceding each shot — the weapon's acoustic pre-charge — which gives it the Kettledrum nickname and is its primary tactical liability. In enclosed spaces, the sound signature is unmistakable and gives experienced opponents a half-second of warning. Suppressor attachment partially masks the report but does nothing to reduce the pre-charge resonance.