XBR55 battle rifle

Were you looking for the BR55 Battle Rifle or the BR55HB SR Battle Rifle? The XBR55 Battle Rifle is a prototype weapon for the BR55 series; "a prototype long barreled weapon with an optical scope."

Overview
The weapon fires 9.5x40mm round from a 60-round magazine It was issued to Staff Sergeants Avery Johnson and Nolan Byrne as well as their militia squads' marksmen, Critchley and Jenkins by Lieutenant Commander Jilan al-Cygni for use during the Harvest event during the year 2525. This was the first weapon to be used against the Covenant and caused the first alien casualty in the Human-Covenant War.

Trivia

 * The prototype resembles the BR55HB SR much more than the standard BR55 model in the cover of Halo: Contact Harvest.
 * When first observed by Avery Johnson, he observed that it had a 60 round magazine. However, the cover shows the ammo count as the standard 36. Johnson may have already fired off a few shots, or this could be an error on the part of the cover artist.

List of appearances

 * Halo: Contact Harvest