Z-390 incineration cannon

The Weapon/Anti-Materiel Z-390 High-Explosive Munitions Rifle, also known as the Incineration cannon, is a Forerunner anti-matériel weapon originally used to combat the Flood.

Overview
The Incineration Cannon was often used to strategically purge infected sites. Prometheans used the Incineration Cannon when assaulting a location believed to contain a Gravemind, or early-forming spore mountains, that were deemed too small for ship weapons but too large for infantry weapons. The Incineration Cannon fires five antimatter-infused streams of concentrated explosive particles, which gather into globular projectiles that oscillate along a straight trajectory. The projectiles detonate and spread upon impact with a target, ricocheting and bouncing in tall but short arc trajectories. It initially holds five whole charges at a time with one shot per charge. Each charge is automatically "loaded" after firing and cool-down. It has been described as "mixing traits of a rocket launcher, shotgun, and flamethrower."

Design details
The weapon possesses an angular design and a metallic casing. It appears to be held together, at least partly, by energy fields as indicated by its self-assembly process and reloading mechanics. Red highlights can be seen while the weapon is self-assembling and throughout the casing once assembly is complete; these highlights grow brighter when the weapon is fired. The weapon also features an integrated optical scope for targeting accuracy. Although the weapon is able to scope, the weapon has no any scope visible on it. It's possible that the scope is on top of the weapon, but the weapon is too much bulky to see it.

Tactics

 * Similar to its UNSC and Covenant counterparts, the Incineration Cannon is best used when shooting the ground in the close proximity of an enemy.
 * In encounters with M808 Scorpion and Type-26 Wraith tanks, players can inflict maximum damage by shooting at their underbellies. If that shot strikes the tank, it will completely destroy it in one hit, because when the main particle explodes, the four remaining ones will go up and explode under the tank, damaging all the parts.
 * Of all the heavy weapons, the Incineration Cannon is the most effective against the Mantis. A single direct hit on the Mantis's cockpit will destroy it; all other heavy weapons require at least two hits.

List of appearances

 * Halo 4
 * Spartan Ops