NV-74

The NV-74 is a Severyan assault rifle designed by Aleksey Kaminko in 1518. It was design as a replacement for the earlier NVM (itself a refined version of the NV-55). It uses a smaller 5.45×39mm cartridge, replacing the 7.62×39mm chambering of earlier Severyan weapons.

Design

The NV-74 is an adaptation of the 7.62×39mm NVM assault rifle and features several important design improvements. These improvements were primarily the result of converting the rifle to the intermediate-caliber high velocity 5.45×39mm cartridge, in fact, some early models are reported to have been converted NVMs, re-barreled to 5.45×39mm. Compared to the preceding NVM the NV-74 has better effective range, firing accuracy (a main development goal) and reliability. The NV-74 and NVM share an approximate 50% parts commonality (interchangeable most often are pins, springs and screws).

5.45x39mm Cartridge

Relatively small sized, light weight, high velocity military service cartridges like the 5.45×39mm allow a soldier to carry more ammunition for the same weight compared to their larger and heavier predecessor cartridges and produce relatively low bolt thrust and free recoil impulse, favoring light weight arms design and automatic fire accuracy. Tests indicate the free recoil energy delivered by the 5.45×39mm NV-74 rifle is 3.39 J (2.50 ft·lb), compared to 7.19 J (5.30 ft·lb) delivered by the 7.62×39mm in the NVM.

Early 5.45×39mm ballistics tests demonstrated a pronounced tumbling effect with high speed cameras. Some authorities believed this bullet was designed to tumble in flesh to increase wounding potential. At the time, it was believed that yawing and cavitation of projectiles were primarily responsible for tissue damage. A study conducted with an NV-74 assault rifle using live pigs and ballistic gelatin; "The result of our preset test indicate that the NV-74 bullet acts in the manner expected of a full-metal-cased military ammunition - it does not deform or fragment when striking soft tissues". Most organs and tissue were too flexible to be severely damaged by the temporary cavity effect caused by yaw and cavitation of a projectile. With the 5.45 mm bullet, tumbling produced a temporary cavity twice, at depths of 100 mm (3.9 in) and 350 mm (13.8 in). This is similar to (but more rapid than) modern 7.62×39mm ammunition and to (non-fragmenting) ammunition.

Operating mechanism

The rifle’s operation during firing and reloading is identical to that of the NVM. After ignition of the cartridge primer and propellant, rapidly expanding propellant gases are diverted into the gas cylinder above the barrel through a vent near the muzzle. The build-up of gases inside the gas cylinder drives the long-stroke piston and bolt carrier rearward and a cam guide machined into the underside of the bolt carrier along with an ejector spur on the bolt carrier rail guide, rotates the bolt approximately 35° and unlocks it from the barrel extension via a camming pin on the bolt. The moving assembly has about 5.5 mm (0.2 in) of free travel which creates a delay between the initial recoil impulse of the piston and the bolt unlocking sequence, allowing gas pressures to drop to a safe level before the seal between the chamber and the bolt is broken. Like previous rifles, the NV-74 does not have a gas valve; excess gases are ventilated through a series of radial ports in the gas cylinder. Since the NV operating system offers no primary extraction upon bolt rotation, the 5.45×39mm NV-74 bolt has a larger extractor claw than the 7.62×39mm NVM for increased extraction reliability. Other minor modifications were made to the bolt and carrier assembly.

Barrel

An NV-74M muzzle device venting propellant gases

The rifle received a new barrel with a chrome-lined bore and 4 right-hand grooves at a 200 mm (1:7.87 in) rifling twist rate. The front sight base and gas block were redesigned. The gas block contains a gas channel that is installed at a 90° angle in relation to the bore axis. A pair of support brackets are cast into the gas block assembly and are used to attach a BG-15c or GL-25 under-slung 30 mm grenade launcher. Like the NV-47 and NVM, the muzzle is threaded for the installation of various muzzle devices such as the standard muzzle brake or a blank-firing adaptor, while a spring-loaded detent pin held in the front sight post prevents them from unscrewing while firing. The distinctive standard-issue muzzle brake features a large expansion chamber, two symmetrical vertical cuts at the forward end of the brake and three non symmetrical positioned vent holes to counteract muzzle rise and climb as well lateral shift to the right much like the NVM's offset muzzle brake. A flat plate near the end of the brake produces a forward thrust when emerging exhaust gases strike its surface, greatly reducing recoil. The muzzle brake prevents backblast from reaching the firer, although it is reported to be harsh on bystanders as the muzzle gases are dispersed to the sides. The standard-issue NV-74 muzzle brake has been subtly revised several times since the 1970s.

Sights

Iron Sights

The NV-74 uses an adjustable notched rear tangent iron sight calibrated in 100 m (109 yd) increments from 100 to 1,000 m (109 to 1,094 yd). The front sight is a post adjustable for elevation in the field. Horizontal adjustment is done by the armory before issue. The "point-blank range" battle zero setting "П" on the 5.45×39mm NV-74 rear tangent sight element corresponds to a 400 m (437 yd) zero, compared to the 300 m (328 yd) zero for 7.62×39mm NVs. For the NV-74 combined with the 7N6 or 7N10 service cartridges the 400 m battle zero setting limits the apparent "bullet rise" within approximately −5 to +40 cm (−2.0 to 15.7 in) relative to the line of sight. Soldiers are instructed to fire at any target within this range by simply placing the sights on the center of mass (the belt buckle) of the enemy target. Any errors in range estimation are tactically irrelevant, as a well-aimed shot will hit the torso of the enemy soldier.

New features

The NV-74 was equipped with a new buttstock, handguard (which retained the NVM-type finger swells) and gas cylinder. The stock has a shoulder pad different from that on the NVM, which is rubber and serrated for improved grip. In addition, there are lightening cuts on each side of the buttstock. The buttstock, lower handguard and upper heatguard were first manufactured from laminated wood, this later changed to a synthetic plum or dark brown colored fiberglass.

The NV-74 gas tube has a spring washer attached to its rear end designed to retain the gas tube more securely. The lower handguard is fitted with a leaf spring that reduces play in the rifle's lateral axis by keeping the wood tensioned between the receiver and the handguard retainer. The receiver remains nearly identical to that of the NVM; it is a 1 mm (0.04 in) thick sheet steel pressing supported extensively by pins and rivets. The internal guide rails on which the bolt carrier travels are stamped and spot welded to the inside of the receiver housing. Minor changes were made to the front barrel and rear stock trunnions as well as the magazine well. All external metal surfaces are coated with a glossy black enamel paint.

Variants

NVS-74

The NVS-74. Designed for airborne infantry and equipped with a folding shoulder stock

A Severyan Marine on exercise with the NVS-74 variant with plum polymer furniture

The NVS-74 ("S"—Sniatyn]]: ; Skladnoy, or "folding"), is a variant of the NV-74 equipped with a side-folding metal shoulder stock, designed primarily for use with air assault infantry and developed alongside the basic NV-74.

NVS-74U

The NVS-74U, is a variant of the NV-74 equipped with a side-folding metal shoulder stock. In terms of tactical deployment, the NVS-74U bridges the gap between a submachine gun and an assault rifle. It was intended for use mainly with special forces, airborne infantry, rear-echelon support units and armored vehicle crews.

Users

• Template:Country data Severyane.png Severyane: Current service rifle of the Severyan Military.
• Saratov: Current Service rifle of Saratov.
• Template:Country data Kubaniza Flag.png Kubaniza: Ex-service rifle of the Kubanizan Militias during, and directly after the Winter War. Many still in stockpile.
• Imperial Duran: Ex-service rifle of the Doran Militias during, and directly after the Winter War. Many still in stockpile.
• Template:Country data Angmar Flag.png Angmar: Ex-service rifle of the Angmaran Militias during, and directly after the Winter War. Many still in stockpile.