LMG, SMG, and NRG (in that order) variants. Base rifle can be found here fav.me/d6gsznr
The XM-220 Automatic Infantry Rifle represents the primary Russian contribution to the ICR projekt. It does away with the M12's Dual-Mode Impingment-Piston in favor of a standard short-stroke gas piston. Fitted with a heavy barrel, telescoping bipod, enlarged muzzle break, and "C-Casket" magazines, it fills an interim LMG role. Nicknamed the "Space M60" by users, it is used in a similar matter to the IAR or the RPK series, as a heavy assault rifle and light machinegun.
It is chambered in the standard 7.5x55mm USIRA +P+ and its barrel has been optimized for Armor Piercing Incendiary loads.
The heavy barrel and forend, combined with the calibrated muzzle break and low rate of fire allows it even better control than the M12, even during short, controlled, 75 round bursts.
On the other end of the spectrum is the MK-12 Strix heavy SMG. The MK-12 is one of Israel's many contributions to the ICR projekt. When asked if they knew the meaning of "Sub Machine Gun" the top engineer on the design team replied "A compact automatic weapon chambered in a handgun cartridge. Five-hundred Smith and Wesson was designed to be used in a handgun."
While not what anyone expected from a SMG, the Strix has proven to be an extremely effective weapon in urban fighting. Mostly used as a night-fighting weapon to make up for its range and accuracy shortcoming, it has earned favor with IDF, FSB, and the USMC for its immense stopping power. The .500 Strix is a derivative of the .500 S&W magnum, altered with the same rim as the 7.5USIRA, this allows the M12 to be converted to a Strix with only a barrel swap. It has been speculated that the reason no pictures surfaced of the Operation Neptune Spear casualties is because of the effects the overpressure 500gr expanding "SCMITR" slugs used for close quarters engagements on soft targets.
The last weapon isn't a true variant, rather the workings of some interns and some broken test weapons. Using a clone of the M2/M3 flamethrower with a booster mechanism, and a propane blowtorch forcibly mated to ICR components, they crafted the "Burninator."
The lead designer was quoted as saying "Jesus-H-Christ, people, we're already in the warcrime-a-day zone, this is just getting ridiculous." The interns reportedly ignored him and continued burning an extremely racist depiction of a WWII era Japanese soldier.
It should be noted that flamethrowers work in the same manner as plasma weapons, projecting a lightweight, superheated material to the target. In both cases, it isn't truly the projected material which damages, but rather the heat off of it.
I dare you not to call it an energy weapon, I'll be waiting in the back lot.