Kelos'vaarda-pattern storm rifle

The Type-55 Directed Energy Rifle/Advanced (T55 DER/A), commonly known as the Storm Rifle, is a Sangheili directed energy weapon.

Overview
Earlier iterations of the weapon were often more specialized and employed by Storm-class units within the Covenant. Eventually, the design was improved by Lodam Armory by 2553 and saw use during Sangheili civil conflicts following the Human-Covenant War's conclusion. The T55 DER/A is considered to be a successor to and direct evolution of the widely used Type-25 plasma rifle; however, it is more similar to the Type-51 plasma repeater, itself an upgrade of the T25, in both form and function. The weapon features such modifications as a rotating modular coil set, a high-mounted cooling shroud, and an extended barrel, which improve upon the features of the standard plasma rifle it replaced the role of.

Both the reformed Covenant and the Swords of Sanghelios use the Type-55 as their standard-issue weapon. The Spartan-IVs deployed aboard the UNSC Infinity also use the Storm Rifle as part of their on-mission loadouts, despite it being of non-UNSC origin.

Changes from Halo 4 to Halo 5: Guardians

 * Fire rate increased. Time to overheat raised accordingly.
 * Increased damage, killing a fully-shielded Spartan in 6 bolts.
 * Smart-scope functionality, allowing more accurate fire.

Trivia

 * "Storm Rifle" is a literal translation of the German "Sturmgewehr", which is generally rendered as "assault rifle" in English, and is in fact the origin of that title. The StG-44 (roughly: Model 1944 assault rifle) was the first assault rifle to see widespread deployment during the latter part of World War II.
 * The Sangheili Ranger action figure included a code that will unlock the "Chill" skin for the storm rifle.
 * Strangely, the Storm Rifle does not count toward automatic loadout weapon commendations in War Games, despite its predecessors all being considered automatic and its firing system being so.
 * The weapon's reticule is similar in both appearance and bloom behavior to the Type-51 plasma repeater from Halo: Reach. The weapons' firing styles are also similar, though the Storm Rifle lacks the "fire through overheat" feature that the Plasma Repeater has.
 * It is possible to use equipment while the Storm Rifle is venting, which has lead to a tactic combining it with the Thruster Pack, whereupon the user fires till it overheats, jets to the side or in reverse to avoid incoming fire, then re-engages their target with the now-cooled weapon.

List of appearances

 * Halo: The Thursday War
 * Halo 4
 * Spartan Ops
 * Halo: Escalation
 * Halo 5: Guardians