Editing Vektor R4 (section)

===Operating mechanism===
The R4 is a [[selective fire]], [[Gas-operated reloading|gas-operated]] weapon that fires from a [[closed bolt]]. 

As with the [[IMI Galil]], the operating system is derived from that of the [[AK-47]]. 

It uses ignited [[Gunpowder|powder]] gases channelled through a vent in the [[Gun barrel|barrel]] to drive a long stroke piston located above the barrel in a gas cylinder to provide power to the operating system. 

The weapon features a self-regulating gas system and a rotary [[Bolt (firearm)|bolt]] breech locking mechanism (equipped with two locking lugs), which is rotated by a helical camming groove machined into the bolt carrier that engages a control pin on the bolt. 

Extraction is carried out by means of a spring-loaded extractor contained in the bolt and a protrusion on the left guide rail inside the [[Receiver (firearms)|receiver]] acts as the fixed ejector.

Internally, the R4 differs from the Galil in the addition of a new gas tube lock to prevent the tube from shaking loose during sustained fire, and the introduction of much wider sear.<ref name="Jane98" /> 

It also has a unique bolt and firing pin, both of which were redesigned to resolve an issue where the firing pin would set off a chambered cartridge with the bolt closed.<ref name="Jane98" /> 

The new firing pin is secured by a polyurethane piece inside the bolt except when positively driven forward.<ref name="Jane98" />

The R4's parts can be interchanged with the Galil ARM with Valmet rifle magazine made for 5.56 NATO caliber being usable for the R4.<ref name="RV3">Roodhorst, The Kalashnikov Encyclopedia III: Serbia-VietnamPage 2961.</ref>