Zastava M91 The Zastava M91 is a semi automatic sniper rifle developed and manufactured by Zastava Arms company , Kragujevac , Serbia . In contrast to its predecessor , the Zastava M76 , the M91 really is a modified copy of the famous Soviet SVD Dragunov semi automatic sniper rifle , the only differences being in a different wooden handguard and the optical scope . Like the SVD , the M91 uses original Soviet 7 . 62x54mmR cartridge , and in service of the Serbian army , it replaced the Zastava M76 sniper , which used the old German 7 . 92x57mm cartridge . History . Zastava ' s website claims that the M91 rifle was designed after a long and careful study of combat tactics and experience of military and police special forces worldwide ; and that its development has been carried out under supervision and in close cooperation with some of the most experienced and capable special and anti - terrorist units . Current modernisation of Serbian forces is proceeding on the basis of a plan designed during the late 1990s known as Model - 21 . It envisages upgrading personal equipment in 26 different categories , of which only five will be imported from abroad . One of the important new developments is the introduction of a series of domestically developed systems such as M91 7 . 62x54mmR sniper rifle ( a requirement resulting from the decision to withdraw the 8x57mm IS chambering used in the Zastava M76 sniper rifle and SARAC M53 machine gun ) . Design details . The M91 is a semi - automatic , air - cooled , detachable 10 - box magazine - fed firearm with a fixed stock . In concept , it is similar to the Russian Dragunov SVD sniper / designated marksman rifle . While the design of the M91 is based upon an elongated version of the Avtomat Kalashnikov 1947 AK - 47 design just like its predecessor , the Zastava M76 , the rifle features several modifications , bringing it closer to its Soviet counterpart , the Dragunov sniper rifle . The separate stock and pistol grip used on the M76 have been replaced with a thumbhole combination stock made of synthetic polymer material resembling that used on the Russian Dragunov SVD rifle . The chambering is the Russian 7 . 62x54mmR cartridge which is the same used in the Dragunov SVD . It is suited for long - range use , and replaced the 8x57mm IS round in Serbian service . Overall , the design of the flash suppressor , the magazine used , the simplified PSO - type rangefinder reticle used in earlier Zrak telescopic sights , even the distinctive shape of the pistol grip and modified bolt carrier ( as well as a milled receiver ) - all these attributes strongly point at SVD as the design ' s template . A side - rail on the left wall of the receiver accepts various telescopic sight s and night optics . The standard daylight telescopic sight for the M91 is the ON - M91 6 x 42 . For low light conditions the rifle can also be equipped with PN 5 x 80 passive sights of the first and second generation of Night vision device s . The optical sight can be removed from the rail and reinstalled without loss of zero . The rifle features adjustable backup iron sights with a sliding tangent rear sight which can be adjusted from 100 m to a 1 , 000 m . These can be employed if the primary optical sight is damaged . Performance . The best results are obtained at ranges up to 800 m . The maximum aiming distance offered by the optical sight and iron sights is 1000 m . For targets of height of 30 cm ( head silhouette ) , the effective range is approximately 320 m , for chest silhouette ( height 50 cm ) the range is 450 m and for a moving silhouette ( 150 cm ) the effective range is 650 m .