An Airtorch Canister is an unusual ammunition type used by Meltaguns and Inferno Pistols that can intensify the heat damage they emit. This ammunition is used most notably in the Koronus Expanse and Calixis Sector. Whilst regular Melta Weapons are known for the tight focus of the superheated beams they generate, Airtorch Canister ammunition allows them to burn even hotter in a barely-controlled reaction that can almost set the air itself on fire.
Indeed, the heat is so intense that it generally overwhelms the weapon's barrel, allowing the blast to escape in a wider swath. However, the more rapid dispersal of the blast halves the weapon's range. This causes the weapon to be prone to overheating, as the heat produced is more than most Melta Weapons can safely withstand.
- Into the Storm - The Explorer's Handbook (RPG), pg. 128