10mm x 25mm GRIM

== Overview ==
10mm x 25mm Gauteng-Rating Implosion Munitions (GRIM) is a hot-loaded high velocity pistol and sub-machinegun round utilized primarily by special operations units and high-level security details within the Iron Coalition Military. The core of the bullet contains a high-viscosity ferro-fluid that when entering the target disperses and creates numerous cavitation bubbles, imploding the impact area. The technology as well as ammunition distribution is highly controlled and protected by the IC, lest it fall into the hands of the PVT.
=== History ===
During the early Y4000s, the 10x25mm round became the basis for experiments on behalf of the Iron Coalition that resulted in the development of the Dapperheid series of experimental munitions. The original case design by Blueblood Munitions Solutions was designated "Dapperheid" and was similar to the GX Beneke case, but with less taper. The experimental cases were made from standard 10x25mm IOD cases which gave a little less capacity than standard Beneke cases because the BMS cases had slightly thicker walls. The later Dapperheid iterations were lengthened compared to the original Dapperheid case and provided a ballistic performance roughly equal to the 10x25mm IOD service cartridge. Many years of technical progress in the field of Cinderite propellants allowed for similar service cartridge performance from a significantly shorter, smaller case with less case capacity. 
==== Ferro-Fluidic Cavitation Technology ====
With the introduction of the new munition into the IC Military, YaoLiang Ballistics saw an opportunity to improve the design as well as test their novel ferro-fluid cavitation technology. By Y4036, their scientists were able to produce a working prototype of a case-hardened projectile surrounding a ferro-fluidic core which, upon fragmenting and expanding, caused significant hydrodynamic cavitation. The significantly improved lethality immediately caught the eye of the IOD, which greenlit further testing of the technology. While the round ultimately has poorer terminal performance than the standard IOD service cartridge, it excelled in close quarters where its lethality was far superior. 
=== Current Usage And Performance ===
As stated before 10mm x 25mm GRIM is primarily used by special operations units and high-level security details within the IC Military. Most recently it has seen use in conflicts in and around Dimock's Jungle, where combat is extremely close quarters due to its thick vegetation and obscured sight lines. It performs well against the local threats found there, such as Pinamoy Warriors and Dryles. Historically, its first use was during the conflict against rebel group Wian's Wrath, where a majority of the fighting was focused around door-to-door close quarters combat.