Heckler & Koch's MP-5/10mm. Based on the full-length 10mm round, as opposed to the truncated .40, and issued with Federal 10mm HydraShok hollow points, this weapon is formidable with stealth and heavy firepower is needed. RAINBOW uses the silenced 10mm MP-5SD/10 in lieu of the MP5SD (9mm) favored by most HRTs.