M149 Magellan

The M149 Recoilless Rifle, also known as the Magellan, is a United Nations Space Command weapon used during the Human-Covenant War.

Background
The only known use of the M149 was during the Battle of Algolis by a Marine with the call sign "Ghost". During the battle, Ghost used a prototypical powered exoskeleton to hold off the Covenant while his fellow Marines and civilians evacuated Algolis. He used the suit's M149 to destroy several Banshees, a Phantom, and significant numbers of Covenant infantry.

Trivia

 * Ferdinand Magellan was a famous 16th century explorer, known for being the first to sail from the Atlantic Ocean to the Pacific Ocean.