The Stoner63 can be found at the beginning of the level Redemptionnear the crashed Huey (with Reflex, Extended Mags and full ammo), and rarely from fallen friendly characters.
The Stoner63 is a "Classified" weapon, meaning it is unlocked by buying all other light machine guns. It has a high rate of fire and relatively low recoil, but a small magazine size, therefore many users use Scavenger or Extended Mags. Also of note is that due to the Stoner63's 40 damage and very high rate of fire, it has the highest damage per second of any gun in the game. This coupled with its decently low recoil makes it perfect for close-to-mid range combat, and also great if burst fired for long distances.
In close quarters, the weapon suffers from a poor hipfire accuracy, however, this can be remedied with Steady Aim. Unlike all other LMGs, the Stoner63 enters ADS in a quarter of a second, the same speed as most assault rifles. Also, in Create-A-Class 2.0, it is held by the character model as though it were an assault rifle rather than a light machine gun. This gun also seems to behave like most assault rifles, with high damage, high rate of fire, low recoil and no damage drop off. The main downside is that it is classified as an