Operating mechanism
The vz. 58 is a selective fire gas-operated weapon that bleeds expanding combustion gases generated in the barrel from the ignited cartridge through a port drilled in the barrel, 215 mm (8.5 in) from the chamber, opening into a hollow cylinder located above the barrel that contains a short-stroke piston. The vz. 58 does not have a gas regulator and the full force of the gas pressure is exerted on the piston head, propelling it backwards in a single impulsive blow. The piston is driven back only 19 mm (0.7 in) when a shoulder on the piston rod butts against the seating and no further movement is possible. There is a light return spring held between the piston shoulder and the seating which returns the piston to its forward position. The gas cylinder is vented after the piston has traveled back 16 mm (0.6 in) and the remaining gases are exhausted into the atmosphere on the underside of the cylinder via two ports. The entire piston rod is chromium-plated to prevent fouling.
The locking system features a falling breech lock hinged from the bolt and housed in the bolt carrier that contains two locking lugs which descend into and engage locking shoulders in the receiver's internal guide rails. The weapon is unlocked by the short tappet-like stroke of the piston rod as it strikes the bolt carrier and drives it rearwards. After 22 mm (0.9 in) of unrestricted travel, an wedge-like surface on the bolt carrier moves under the breech locking piece and lifts it up and out of engagement with the locking recesses in the steel body. The breech locking piece swings up and this movement provides the leverage required for primary extraction. The breech block is then carried rearwards extracting the empty cartridge casing from the chamber. A fixed ejector passes through a groove cut in the underside of the bolt and the case is flung upwards clear of the gun.
Features
The spring-loaded extractor and firing pin are both housed inside the breech lock, while the fixed ejector is located at the base of the receiver.
The weapon does not have a conventional rotating hammer but is striker-fired and the striker is a steel bar hollowed from one end almost throughout its entire length to accommodate its own operating spring. At the open end of the striker, a plate is welded and there is a groove cut in each side of this to slide on the receiver guide rails. This hammer-striker enters the hollow bolt and drives a fully floating firing pin forward with each shot.
The rifle uses a trigger mechanism with a lever-type fire mode selector, which is also a manual safety against accidental discharge. When the selector lever is placed in its rear position ("1"—single fire) the sear is disabled and the left striker catch is rotated by the disconnector, which is depressed by the bolt carrier after every shot and is therefore disconnected from the striker catch. The forward setting of the selector lever ("30"—automatic fire) disables the disconnector, and the left striker catch meshes with the sear mechanism. The center ("safe") setting with the selector lever pointing vertically downwards, mechanically lowers the trigger bar and the disconnector so there is no connection between the trigger and the semi-automatic sear which holds the hammer. The rifle also has an internal safety, which prevents the weapon from discharging when out of battery. The right striker-hammer catch disables the striker-hammer, and it can only be released by pulling the charging handle back and cocking the weapon.
The weapon is fed from a detachable box magazine with a 30-round cartridge capacity and made from a lightweight alloy. When the last round from the magazine is fired, the bolt will remain locked open on the bolt catch, activated by the magazine's follower. The magazine release tab is located at the base of the receiver on the left side, behind the magazine well. The bolt carrier has a built-in guide rail used for reloading from 10-round stripper clips (from the SKS rifle). Despite their similarity, vz. 58 magazines are not interchangeable with those of the AK-47 and its derivatives.
Sights
The rifle's iron sights consist of a fully adjustable front post and a tangent rear sight with a sliding notch with range denominations from 100 to 800 m, graduated every 100 m. Besides this, the left side of the rear sight leaf is marked with the letter "U" (univerzální meaning "universal"), for snap shooting, firing at moving targets and night combat at ranges up to 300 m. The front sight base also serves as a mounting platform for the vz. 58 edged bayonet.
Accessories
As of 2009 several Modernization Accessories have been manufactured for the vz. 58 platform from companies such as Neit Arms Inc and North Eastern Arms. Accessories include; Tactical Bolt Release, Extended and Ambidextrous Magazine Releases, Ambidextrous Selectors, Handguard sets with Lower 1/3 Cowitness, a wide assortment of Mounting options and Muzzle Brakes. Many of these items are currently being used by PMC Companies in the Middle East.
Additional equipment supplied with the rifle includes: 4 spare magazines, a magazine pouch, vz. 58 bayonet and scabbard, cleaning brush, muzzle cap, oil bottle, unified sling, front sight adjustment tool and a threaded blank-firing adaptor.
Variant
- Vz. 58 P: Standard fixed stock.
- Vz. 58 V: Metal folding stock version for vehicle crew and airborne units.
- Vz. 58 Pi: Has a mounting interface for an infrared night vision NSP-2 sight, fixed stock, cone flash hider and folding bipod.
- Automatická puška ("automatic rifle") AP-Z 67: Experimental 7.62x51mm NATO caliber version developed in 1966.
- Útočná puška ("assault rifle") ÚP-Z 70: Experimental 5.56x45mm NATO version developed in 1970.
- Experimentální zbraň ("experimental weapon") EZ-B: Experimental bullpup prototype developed in 1976.
- Ruční kulomet ("light machine gun") codename KLEČ ("dwarf pine"): Experimental variant with a 590 mm barrel (similar to RPK), developed in 1976.
- Lehká odstřelovačská puška ("light sniper rifle") vz. 58/97: Experimental marksman rifle developed by VTÚVM Slavičín.
- Samopal ("submachine gun") vz. 58/98 "Bulldog": 9x19mm Parabellum variant developed by VTÚVM Slavičín.
- CZH 2003 Sport: Semi-automatic only variant for civilian consumption. Available with either a standard (390 mm) or shortened (295 mm) barrel. Limited production was made for the civilian market in Canada with an extended barrel length of (490 mm).
- CZ 858 Tactical: A semi-automatic variant designed for the civilian market in Canada. Available with standard (390 mm) barrel length on the restricted -4V version, or extended (482 mm) barrel length on the -2 version. The barrel is not chrome-lined in the -2 version unlike the military and -4V version. External components have a new varnish coat (identical to the coating used on original military rifles).
- FSN Series: Civilian semi-automatic variants. Available in standard (FSN-01, 390 mm), with or without folding stock (FSN-01F and FSN-01W, which has a wooden cheek piece), or shortened (279 mm) barrel lengths (also with folding stock), outer parts are blued.
- VZ-58 Sporter Series: Available in 5.56 NATO, or 7.62x39mm, these carbines are made by Czech Small Arms, and not Česká Zbrojovka.
| Vz. 58 | |
|---|---|
| Type | Assault rifle |
| Place of origin |  Czechoslovakia |
| Service history | |
| In service | 1959–present |
| Used by | Afghanistan, Angola, Cuba, Cyprus, Czech Republic, Eritrea, Ethiopia Guatemala, Guinea, India, Iraq, Libya, Mozambique, Slovakia Somalia, Tanzania |
| Wars | War in Afghanistan (2001–present) |
| Production history | |
| Designer | Jiří Čermák |
| Designed | 1956–1958 |
| Manufacturer | Česká Zbrojovka |
| Produced | 1959–1984 |
| Number built | Approx. 920,000 |
| Specifications | |
| Weight | 2.91 kg (6.42 lb) |
| Length | Vz. 58 P: 845 mm (33.3 in) Vz. 58 V 845 mm (33.3 in) stock extended / 636 mm (25.0 in) stock folded 1,000 mm (39.4 in) with bayonet fixed |
| Barrel length | 390 mm (15.4 in) |
| Width | 57 mm (2.2 in) stock extended 72 mm (2.8 in) stock folded |
| Height | 255 mm (10.0 in) |
| | |
| Cartridge | 7.62x39mm M43 |
| Action | Gas-operated, falling breechblock |
| Rate of fire | 800 rounds/min |
| Muzzle velocity | 705 m/s (2,313 ft/s) Muzzle energy: 1988 J |
| Effective range | 100–800 m sight adjustments |
| Maximum range | 2,800 m |
| Feed system | Staggered 30-round detachable box magazine, weight 0.19 kg (0.42 lb) unloaded |
| Sights | Open-type iron sights with sliding rear tangent and shrouded front post 353 mm (13.9 in) sight radius |
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