The Serbu ROF was a prototype high rate of fire 9mm submachine gun capable of firing 1200rpm. As of when these pictures were taken, the ROF has had over 3,000 rounds of ammo fired through it. Since the ROF was built after May 19, 1986, it is considered to be a "post-`86" dealer sample machine gun which can only be bought by licensed manufacturers, dealers, government entities or law enforcement. Needless to say, there isn`t really enough of a market to warrant making the ROF a production gun.
The ROF has a fairly standard open bolt type of action, and was designed and built primarily as an exercise in building a complete gun, mostly from scratch. The only parts which were bought and left unmodified are the flash hider and the pistol grip. Those parts, as well as the trigger, safety and barrel blank, are from an AR-15. Virtually everything else, including the springs, was fabricated. The upper receiver is made from 1.375 OD, .058 wall 4130 DOM tubing. The bolt is made of 8620 which is case hardened to Rc 55-57, with a case depth of .015. The lower receiver is a weldment made from a combination of bent-up mild sheet steel and machined 1018 steel. The barrel was made from a section of AR-15 9mm barrel, though 9mm blanks would have worked just as well. The main recoil spring was wound from .041 diameter music wire. The most unique feature of the ROF is the magazine insert. The vertical line just forward of the trigger guard is where the magazine insert may be separated from the rest of the lower receiver. The bolt was designed to accommodate a range of cartridges and magazines; the magazine insert seen in the picture allows the ROF to use British Sten magazines. The next magazine insert to be made will accept a PPS-43 mag, which holds 7.62x25mm ammo. Obviously, a barrel change is required to complete the conversion.