This is the TWSH RA(AM)-88 Recoiless Rifle, better known as the RAM-88, it a anti material rifle used by the Baven Illumate, one of the factions of the Black Age Universe. This rifle is basically used when you have to take out something like a tank, or a guy you really don't like, from seven or eight miles away. The way it works is it fires two rounds, one from each of those massive barrels. Other than the concept of hammer pairs, and the resulting massive trauma that ensues, you can mix and match ammunition types, like mixing a high velocity anti armor round with a incendiary round, the faster anti armor round makes a hole while the incendiary round goes through the hole and wreaks havoc on the inside.
Wikipedia: "Recoilless rifles are capable of firing artillery-type shells at a range and velocity comparable to that of a normal light cannon, although they are typically used to fire larger shells at lower velocities and ranges. " in effect, a rocket launcher. What you are describing here is simply a large caliber (.78, to be specific) sniper's rifle. also, not only is the weapon's name incorrect, but the inaccurate name is misspelled (recoilless has two L's.) Still pretty awesome, though.
I'll admit that the use of the term recoilless is a bit stretched, but still accurate. It operates in a similar manner to the M136-CS, except instead of a water based counter-charge the weapon uses a kinetic dampener in conjunction with a spring return recoil assembly similar to that seen on artillery pieces.
Ill take it. What dose it fire? .50 or bigger?
Pretty sick man!