Editing Vektor R4 (section)

==Design details==
{{See also|IMI Galil}}
The weapon is a licensed variant of the [[IMI Galil]] assault rifle<ref name="woźniak">Woźniak, Ryszard. Encyklopedia najnowszej broni palnej – tom 4 R-Z. Bellona. 2002. pp9–10.</ref><ref>{{cite book|url=https://books.google.com/books?id=Eq2Dnj4sDZIC|title=Rifles of the World|author=John Walter|page=141|year=2006|publisher=Krause Publications|isbn=0-89689-241-7}}</ref> with several modifications; both the [[Stock (firearm)|stock]] and [[Magazine (firearm)|magazine]] are now made of a high-strength [[polymer]] and the stock was lengthened, adapting the weapon for the average South African soldier.<ref name="woźniak" /> 

Other detailed differences include the R4's lack of a carry handle and a number of modifications made to its internal operating mechanism.<ref name="Tilstra" />

===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>

===Features===
[[File:FIB-training-01.jpg|thumb|left|A South African soldier, part of the [[United Nations|UN]] [[United Nations peacekeeping|peacekeeping force]], armed with an R4 during a training exercise in 2013]]
The R4 is hammer-fired and uses a trigger mechanism with a 3-position fire selector and safety switch. 

The stamped [[Sheet metal|sheet steel]] selector bar is present on both sides of the receiver and its positions are marked with letters: "S"— indicating the weapon is safe, "R"—single-fire mode ("R" is an abbreviation for "repetition"), and "A"—fully automatic fire. 

The "safe" setting disables the trigger and secures the weapon from being charged.

The R4 is fed from a steel or synthetic box magazine with a 35-round cartridge capacity (designed to use the [[5.56×45mm NATO]] cartridge with the M193 projectile).<ref name="Jane98" /> 

Steel magazines were initially manufactured for the weapon, but this was replaced by a nylon and fiberglass copy to reduce weight.<ref name="Jane98" /> A 50-round steel magazine was produced during the 1980s.<ref name="Jane98" />

The R4 has a side-folding tubular stock, which folds to the right side of the receiver. The rifle's handguard, [[pistol grip]], magazine, stock arms and shoulder pad are all made from a synthetic material, making it lighter in weight than the equivalent original Galil, which uses heavier metal and wood in these components.

For regular field maintenance and cleaning, the firearm is disassembled into the following components: the receiver and barrel group, bolt carrier, bolt, return mechanism, gas tube, receiver dust cover and magazine.

===Sights===
The rifle has conventional [[iron sights]] that consist of a front post and a flip-up rear sight with 300 and 500 m apertures. 

The front sight is adjustable for windage and elevation and is installed in a durable circular shroud. 

The rear sight is welded at the end of the receiver's dust cover. For nighttime use, the R4 is equipped with self-luminous [[tritium]] light dots (exposed after placing the rear sight in an intermediate position) installed in a pivoting bar to the front sight base, which folds up in front of the standard post and aligns with two dots in the rear sight notch.

=== Upgrade ===
DLS has introduced remanufactured models of the R4, R5, R6 that have [[Picatinny rail]]s. DLS has also introduced grenade launchers, grips and other underbarrel attachments.<ref>{{cite web|url=http://www.defenceweb.co.za/index.php?option=com_content&view=article&id=9747:denel-showcases-a-21st-century-r4-assault-rifle-at-aad&catid=50:Land&Itemid=105 |title=Denel showcases a 21st Century R4 assault rifle at AAD |publisher=DefenceWeb |date=24 September 2010 |access-date=1 October 2012}}</ref>