The ER7 RFW is a rail gun (or gauss rifle) capable of accelerating a ferro-magnetic projectile at ludicrous speeds, making it deadly in every aspect. The speed at which the projectile exits the barrel makes for virtually no bullet drop and instantaneous travel, making ArmA 2 look more like your regular FPS game. Due to this the spawn rate is nearly as low as a possible 1 per server restart. As with the AS50 and M107, it has a large amount of raw power, but is not capable of punching through walls or enemies (though it does go through vehicle doors and windows), due to ArmA 2 engine limitations.
This weapon has two variants: one with a red dot and one with a 4x scope. Both seem to be innaccurate, probably for balance purposes.
It is only found in Namalsk, and is treated as an "alien weapon" by the community. The model and sound effect were taken from the Gauss Rifle from Crytek's game Crysis (2008).