The XJ-9 General-Purpose Assault Stonethrower, more commonly marketed under the name Heartseeker, has been the standard general infantry weapon of Aux Sedonis for nearly eighty years. It is a Stonethrower that offers high reliability and endurance in all field conditions, and can be used for a variety of non-specialized battlefield roles. It is typically used in greater quantities by general infantry to immediately respond to a multitude of threats while protecting squad specialists.
After being in development for several years, the XJ-9 became the standard arm of the Aux Sedonis Armed Forces in 3479, and reached prominence in all of its arks before 3500. It was designed to be fully-compatible with ammunition and gas mixtures of its predecessor, the RJ61, allowing the two weapon to be used in parallel until the transition was complete.
The XJ-9 is capable of automatic fire, with a selector toggling between single-shot and fully-automatic mode. It is capable of firing a maximum of 600 rounds per minute, but has a more practical field-rate of around 40 rounds per minute in semi-automatic mode, and 100 rounds when fired automatically. Its standard magazine carries seventy ultra-dense 8mm rounds with a cubic boron nitride-derived head, and its gas tank can accelerate seven magazines to supersonic velocity before pressure degrades and performance decreases.
The XJ-9 has a selectable thermal penetration mode, allowing excess gas to be used to charge rounds with a significant amount of heat, though cutting down on total number of rounds that can be fired on a full tank by half. In this mode, rounds cause significant behind-armor damage to armored infantry, and are capable of taking out lightly armored vehicles.
Because of its pneumatic action, non-standard rounds can be easily utilized, while allows foreign nations to produce their own unique ammunition variants. This includes metal rounds, though using such rounds has a negative impact on the performance of the thermal penetration mode.
"Cut to the heart of the issue."
-XJ-9 Advertising Campaign
The XJ-9 has been the most-produced weapon by Aux Sidonis for the last century, being exported to foreign nations and Zeconian firms alike. Its long lifespan and long production history has contributed to it being one of the most widely-employed weapons in the galaxy, seeing use everywhere from the Levant and Kingdom of Knotar to the Bolaemia Bureaucracy. Its legendary durability and reliability makes it a popular choice among Kuhn pirates.
The XJ-9 is one of the weapons integrated into the Worldshaker 5.