Zastava M70 The Zastava M70 is an assault rifle developed and produced in Yugoslavia , nowadays Kragujevac , Serbia by Zastava Arms company . The M70 is actually a modified copy of the Soviet AKM assault rifle and it became the standard issue weapon in the Yugoslav People ' s Army in 1970 . The M70 is an air - cooled , magazine - fed , selective fire rifle . History . Initial development of a domestic AK variant began c . a 1959 , and the first models submitted by Zastava for military field trials were with the early M64 series of rifles with milled receivers , threaded barrels , familiar Yugo handguards , gas cutoffs for grenade launching , and several other diversities from the mainstay AK design , such as a bolt hold open device on the right side of the receiver , and a charging handle that appeared different from other AK models . Though performances were satisfactory , the Yugoslav military did not adopt the rifle as the standard infantry armament . In 1970 , a second opportunity emerged , and Zastava was given the go ahead to begin with army funded mass production of the AP M70 and M70A series ( , M70 Automatic Rifle ) of which the M70A was the folding stock version . Before the larger models of these rifles were made , cost - cutting measures in production resulted in the removal of the internal bolt hold open , and relocation to the magazine follower . In addition , the usual placement of the barrel through threading into the receiver was replaced by the cheaper method of pressing and pinning the barrel into the receiver . Rifles produced with these new features were known as models AP M70B ( fixed stock version ) , and M70AB ( folding stock version ) . As with the M - 70 series of automatic rifles , these models failed to be produced in larger quantities before further cost - efficiency production measures gave way to yet another model . This time the milled receiver was replaced by a stamped receiver of 0 . 9mm thickness , a firing rate reducer was added to the trigger group , and the muzzle brake replaced the muzzle nut that originally came on the two prior models . Yugoslavian AKs produced with these features were named models AP M70B1 ( fixed stock ) and M70AB1 ( folding stock ) . These models eventually failed to mass - produce as well , before final alterations to the M70 rifle design resulted with the AP M70B2 ( fixed stock ) and M70AB2 ( folding stock ) models . These last two models featured a thicker 1 . 5mm stamped receiver and bulged front trunnion , which was intended to strengthen the rifle in order to make it more suitable for frequent grenade launching . These two models would become the most widely produced of the M70 series , and in turn the most widely used model used by the YPA , as well as the various armed groups fighting in the Yugoslav wars of the 1990s . Parts kits imported into the U . S . however , show markings that appear to contradict the final fixed stock model name . On these kits the bulged , thicker stamped receiver model is actually the M70B1 model . All of the M70 models share the grenade launching ability with gas cutoff , the lengthened wooden handguard with 3 cooling slots , iron sights with flip - up illuminating elements , initially filled with phosphorus and later with tritium ( Which is used on the current production M70 ' s ) , to improve aiming at night ; the plunger that keeps the receiver cover in place during grenade launching , and a non - chrome lined barrel . Fire selectors have R markings for automatic fire ( The R stands for " rafalna " , " burst fire " ) and J for semi - automatic fire ( The J stands for " jedinačna " , " single " ) . Design and features . The M70 can easily be told apart from other AK rifles by the three cooling slots on the foregrip , the light - coloured teak furniture and the black rubber buttplate on fixed - stock M70s . The M70s also have a grenade - launching sight and gas cut - off on the gas block , and are capable of launching rifle - grenades . To launch them a 22mm diameter grenade launching adapter is screwed on in place of the slant brake or other muzzle device . The receiver of the M70 is 1 . 5mm thick , compared to the ~ 1mm receiver of the AKM , making it more rigid . Likewise , the barrel is not chrome - lined , making it more accurate than a standard AKM , but at the cost of increased susceptibility to corrosion . The lack of chrome lining is consistent with other Yugoslavian built rifles of Soviet design ( such as the Yugoslavian M59 or M59 / 66 ) .