IRA-90

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IRA-90
Infanteria Rifle Automatico Modelo 1990
Stgw 90.jpg
A IRA-90 in the stock folded and open position
Type Assault rifle
Place of origin
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Temuair
Service history
In service 1990 - Present
Used by  Temuair
Production history
Designed 1983 - 1990
Manufacturer Brais Roi Arsenal
Unit cost $462
Variants IRA-90, IRA-90M, IRA-90C, IRA-94 Curto, IRA-90TE,
Specifications
Weight 4.1 kg (9.04 lb)
Length Overall: 998 mm (39.3 in)
Folded: 772 mm (30.4 in)
Barrel length IRA-90: 528 mm (20.8 in)

Cartridge 5.65x49
Action Gas operated, rotating bolt
Rate of fire 700 RPM
Muzzle velocity 911 m/s (2,989 ft/s)
Effective range 400m
Feed system 5, 10, and 30 round box magazines
Sights Iron sights adjustable from 100 to 400 m, rear rotating diopter drum with tritium inserts, hooded front sight, models equipped with flat top rails include fixed front post and flip up rear sight.

The IRA-90 (Infanteria Rifle Automatico Modelo 1990, or Infantry Automatic Rifle Model 1990) is an assault rifle developed by Brais Roi Arsenal of Temuair and has been in service with the Armed Forces of the Temuair Empire since 1990. It replaced the nations older <something> in Aisling service, which had been adopted in 1948. It is based on the older XIRA-73, which was never adopted.

History and development

Design

A diagram of long-stroke gas operation system

The IRA-90 is a hammer fired, selective fire assault rifle chambered IN 5.65x49 mm and firing from a closed bolt. It has a gas-actuated piston-driven long stroke operating system derived from the earlier XICA-73 rifle, which uses burnt powder gases vented through a port in the barrel to power the weapon's moving parts. Once inside the gas cylinder, propellant gases pass through an L-shaped channel machined in the piston head and are directed forward towards the gas valve. The pressure build-up in front of the piston head pushes the piston and bolt carrier rearward. As the piston is driven back, the gas port and the L-shaped channel move out of alignment, cutting off the supply of gas to the cylinder. Surplus gas and powder residues are evacuated through an exhaust port in the gas cylinder. This system ensures that only the precise volume of gas required to overcome the mass and resistance of the rifle's moving assembly is admitted from the barrel. The manually adjustable gas valve has two settings, one for normal operation, and the second setting for use in the presence of heavy fouling or icing.

The rotary bolt locking mechanism, which was taken directly from the earlier XICA-73, consists of two steel locking lugs that engage locking recesses in the breech A spring-loaded extractor is incorporated into the bolt while a fixed protrusion on one of the receiver's internal guide rails ejects the spent cartridge casings.

The rifle features an ambidextrous safety and fire sections witch with four positions; Safe, Single, Burst, and Automatic (0/1/3/30). The trigger guard is capable of folding down to facilitate the use of heavy gloves when firing. Magazines are produce in 5, 10, 20 and 30 round versions and are constructed of high impact polymers. The newer IRA-90M utilizes SKANSTAN or OSTAN magazines over the prior proprietary magazine. A hold-open device will lock the bolt open on an empty magazine.

The side-folding skeletal stock is also adjustable to four different lengths. The hinged stock is firmly locked in the folded position by a socket in the butt which clips into a plastic stud on the handguard; a firm pull will release the stock which is then swung into the closed position and locked by a button catch. The forward handguard is equipped with grooves to accept a lightweight aluminium bipod.

The heavy, cold hammer-forged barrel is screwed into the receiver and is equipped with a slotted "bird cage" type flash suppressor that is also used to launch rifle grenades (using standard, live ammunition) or attach a knife bayonet (the bayonet is supported by a lug located at the base of the gas block).

The standard IRA-90 and IRA-90M is compatible with bayonet and is capable of firing riffle grenades. This assault rifle can be equipped with the MAT MLE-40 40 mm underbarrel grenade launcher. This grenade launcher can be operated independently from the rifle.

Variants

IRA-90

First production variant

IRA-90C

Carbine variant for use by airborne and air assault forces. It features a shorter barrel than the standard IRA-90 and does not include the integrated bipod, but can still utilize both a bayonet and rifle grenades.

All IRA-90C models in service have been upgraded with the IA-90M, but retain the C designation.

IRA-94 Curto

Ultra-short version for special force and personal defense. It has a shorter 226 mm (8.9 in) barrel (with an open, 3-prong flash suppressor) and gas tube, ventilated handguards and was the first IRA-90 variant to feature a redesigned bolt carrier group that was integrated with the piston rod to form a single moving assembly, a feature that is now standard on all ITA-90 rifles. It can fire standard 6.65x49 mm rounds, but a specialized round designed for barrel lengths under 16 inches, exists. It can not utilize a bayonet or rifle grenades, though a version with a longer 346 mm (13.6 in) barrel exists and can utilize these features.

IRA-90M

An IRA-90M

Adopted in 2004, one of the primary features of the IRA-90M was the switch from proprietary magazines to Skanderian Union (SKANSTAN) standard magazine to better facilitate inter-service cooperation between member states. Other internal features were also improved, including the repositioning of the recoil spring to wrap it around the piston rod; an improvement already featured on the IRA-94 Curto as well as an integrated bipod.

IRA-90TE

The IRA-90TE is utilized as a squad designated marksmen rifle. This accurized rifle has a refined two-stage trigger (the pull force was reduced from 35 N (7.9 lbf) to 15 N (3.4 lbf), a heavy, hammer-forged 650 mm (25.6 in) long barrel with a 254 mm (1:10 in) rifling twist rate (it has no flash hider) and is used exclusively with telescopic sights. The new folding stock has an adjustable cheek piece and a spacer system on the butt, the ergonomic pistol grip's angle of inclination can be regulated and the bipod features a height and cant adjustment mechanism.

Version comparison

Version Weight Length Barrel length Muzzle velocity Notes
IRA-90 4.1 kg (9.04 lb) Overall: 998 mm (39.3 in)
Stock Folded: 772 mm (30.4 in)
528 mm (20.8 in) 911 m/s (2,989 ft/s)
IRA-90M 4.1 kg (9.04 lb) Overall: 998 mm (39.3 in)
Stock Folded: 772 mm (30.4 in)
528 mm (20.8 in) 911 m/s (2,989 ft/s)
IRA-90C 3.40 kg (7.5 lb) Overall: 833 mm (32.8 in)
Stock Folded: 607 mm (23.9 in)
454 mm (17.9 in) 850 m/s (2,788.7 ft/s)
IRA-94 Curto 3.2 kg (7.1 lb) Overall: 504 mm (19.8 in)
Stock Folded: 730 mm (28.7 in)
226 mm (8.9 in) 725 m/s (2,378.6 ft/s) Uses the GVPAT-96/41 5.65x49 mm round but can fire other 5.65x49 mm loads.
IRA-90TE 7.02 kg (15.5 lb) Overall: 1,130 mm (44.5 in)
Stock Folded: 905 mm (35.6 in)
650 mm (25.6 in) 940 m/s (3,084.0 ft/s)

Operators

An IRA-94 Curto

See also