The M7S caseless sub machine gun

The M7S is a variant of the M7 Caseless Submachine Gun, which fires 5 x 23mm M443 Caseless Full Metal Jacket ammunition. This variant features an external flash and SS/M 49 sound suppressor on the barrel along with a flashlight. Recoil from all but sustained fire is very controllable. Although the M7 submachine-gun is primarily issued to vehicle crews, it is also a favorite of commando teams in its sound suppressed version. Sustained automatic fire tends to cause the muzzle to “walk” upwards as recoil compounds. Submachine guns, while not accurate over long distances, are particularly effective in close quarters. Muzzle flash is significantly decreased, and firing the weapon gives a barely noticeable sound, increasing stealth applications for the M7S Submachine Gun and increasing accuracy from decreased recoil making the weapon more efficient at medium-long range. It is a good weapon for stealth and hit-and-run missions.I have got this info from halopedia.com