Weapons in Mass Effect are powered by Element Zero and Mass Accelerators. Each gun has a ball of metal inside, when you pull the trigger it shaves a bullet the size of a grain of sand off the metal ball and combines with the Element Zero to fire at hypersonic velocities. This method removes the need for any ammunition or reloading. However, all guns will overheat if you fire too many shots too quickly.
 Mass Effect
There are 5 different types of weapon in Mass Effect. With the exception of Grenades, each weapon has around 10 variations from different Manufacturers with 10 levels of power for each type.
 Weapon Types
 Mass Effect 2 and Mass Effect 3
There are 6 different types of weapons in Mass Effect 2 & Mass Effect 3. There are varying number & sub-types for each weapon. The weapon system has changed, as weapons now use heat sinks, which runs similar to an ammo system. Each heat sink allows a "clip" of ammo to be fired, before it is ejected and replaced with a new heat sink. Heavy weapons also use different power cells to those of normal weapons.