IMBEL 5.56 mm rifle developments

This early IA2 prototype is fitted with a longer barrel than the current 330mm (350mm, with flash hider) unit, while its polymer foldable stock, also adjustable for length, has now given place to a simpler design.

Way back in the early 20th Century, the world’s armies were generally equipped with bolt-action rifles in calibers of around .30 in — exemplified by rounds such as the U.S. .30-06, the British .303 and the German 7.92x57mm – which offered a range (effective or so) of around 1,000 meters. This remained virtually unchanged during WWI, but rifleman theory began to be modified in WWII. Not only were semi-automatic rifles introduced by the U.S. (the M1 Garand), the Soviet Union (SVT-40), and Germany (G43), but the German Wehrmacht later also broke new ground with the service introduction of its new family of MP-44/StG-44 assault rifles and the corresponding 7.92x33mm “KurzPatrone” round. The Russians soon followed suit with their AK-47/AKM rifles in 7.62x39mm caliber. Post WWII rifle cartridge evolution included the NATO adoption of the 7.62x51mm round in the mid-1950s, followed by the U.S. choice of the smaller 5.56x45mm M193 cartridge for the AR-15/M16 rifle which debuted in combat a decade later during the Vietnam War. The early 1980s saw NATO adopting the slightly-modified SS109 (M855) 5.56x45mm round it had chosen as standard for rifle use. Then, the “five-five-six” quickly became the caliber of choice of almost every military force in countries outside the Soviet
area of influence.

Pretty much like a great number of the world’s armies, the Exército Brasileiro (Brazilian Army) was widely equipped with 7x57mm bolt-action Mauser rifles of different origins (CZ, DWM, FN, Mauser, Oviedo) during the earlier periods of the 20th Century. In the mid-1930s, the service’s Fábrica de Itajubá (Itajubá Factory), located in the city of the same name in the Minas Gerais State, started the local manufacture of the Mauser M1908/34 rifle, a 200 mm shorter variant of the omnipresent 1908 model that was locally called the “Mosquetão” (Musketoon). While fighting alongside U.S. 5th Army forces in the Italian front in World War II, however, troops of the Força Expedicionária Brasileira (Brazilian Expeditionary Force) were armed with M1903 Springfield and M1 Garand rifles, plus M1918 BARs and Browning M1917/M1919 machine guns. Following the conflict, the Army not only kept all those weapons but immense supplies of .30-06 ammo as well, which prompted it to decide to abandon the older 7x57mm cartridge as its standard round. Local rifle production followed suit, and Fábrica de Itajubá soon introduced its Mq .30 M1949 and a later Mq .30 M954 bolt-action rifles, both in .30-06.

This 1984-85 prototype marked the shift to the FAL tilting-block breech locking system for the IMBEL 5.56x45mm rifle venture and the use of the characteristic tubular folding stock of the larger-caliber gun. Note the short wooden handguard and the unprotected gas cylinder.

In the early 1950s, an attempt was made at the Itajubá facilities to make a Brazilian variant of the German G43 semi-automatic rifle chambered to the U.S. round, this resulting in a very small batch of the so-called Mosquetão Semi/Automático .30 Modelo 1954 (Mq S/Aut. .30 M954) for test purposes, the guns apparently employing a BAR-type 20-round detachable box magazine. Another similar G43 conversion, which received no designation, was also made by the Army’s Arsenal de Guerra do Rio de Janeiro (Rio de Janeiro War Arsenal), but both ventures were unsuccessful for reasons never clearly explained.

The official adoption of the 7.62x51mm cartridge by NATO in 1954 was a clear indication of what would happen in most Western nations in the decades to come. Exactly ten years later, in 1964, the Brazilian Army announced not only its shift to that round but also the choice of the FN FAL rifle to equip its troops, and this would include full local manufacture of the Belgian gun. This, of course, would be carried out by Fábrica de Itajubá, and activities began in August of that year to get the program started. This involved the acceptance of an initial batch of 48,000 complete FALs, 2,000 units in KDCs (Knocked Down Components), and 2,000 FAPs (Fuzis Autmáticos Pesados, Heavy Automatic Rifles), the heavy-barrel SAW model), plus ammunition, rifle grenades, production tooling, technical drawings, etc. On May 5, 1977, State-owned IMBEL – Indústria de Material Bélico do Brasil was created, and two months later the Itajubá Factory was incorporated to the new company as Filial Número 5 – Fábrica de Itajubá. Full nationalization of the Fz 7,62 M964 (fixed stock) and Fz 7,62 M964A1 (foldable stock) FALs had been achieved in 1973, the type also having been adopted by the Marinha do Brasil (Brazilian Navy) and its Corpo de Fuzileiros Navais (Marine Corps) in 1978 as a replacement of their FN SAFN-49s in .30-06 caliber that had been in service since 1957. For the record, the Força Aérea Brasileira (Brazilian Air Force) adopted the 5.45x45mm Hecker & Koch HK33 in rifle and carbine variants in the very early 1970s, becoming one of the first international users of this German weapon.

The 1983 Fz 5.56 IMBEL MD1 compared to a standard fixed-stock FAL.

Mention should also be made of the Mq 7.62 M968, the so-called Mosque-FAL, a Fábrica de Itajubá conversion of the local Mausers to the 7.62x51mm caliber that also incorporated modified sights (FAL-type, rear; G3-type, front), a standard FAL 22-mm flash hider fitted to the 415 mm barrel, a folded-down bolt handle, and a rubber buttplate. Thousands of those rifles were made in Itajubá, and found their way into Brazilian Army second-line units, mainly those involved in training.

The first move towards a Fábrica de Itajubá-made 5.56×45 mm rifle materialized in mid-1983, when the company completed the prototype of a selective-fire rifle chambered to that round, the Fz 5.56 IMBEL MD1, that had been designed and built by the company’s Oficina de Protótipos (Prototypes Workshop). Not surprisingly, it incorporated more than a few FAL components, the fixed stock and grip/trigger group being the more evident. However, the gas-operated piston system parted from the Belgian rifle’s tilting breechblock component, and employed a rotary bolt with multiple locking lugs, the 20-round steel magazine being a proprietary type. The gun featured a redesigned lower receiver fitted with a stamped magazine housing, as well as a perforated jacket that involved both the gas tube and part of the 464 mm-long barrel, which was fitted with a NATO-standard 22mm flash hider. Loaded weight was about 4 kg, heavy all right, but weight reduction along the development phase was a goal of the small design team. The author had a chance to fire that single prototype at the factory range in June 1983, and pretty much liked how it handled and worked. Its moderate cyclic rate of fire of roughly 700 rounds per minute plus the relatively high weight (for the caliber at hand) was a plus when it came to controllability in full auto.

This FIL-97 rifle, while introducing a polymer-made foldable stock, still retained typical FAL components, such as the pistol grip/trigger assembly and the synthetic handguard. The FILC-97 carbine, on the other hand, broke new ground in the general configuration department.

It should be pointed out that the initial development of this weapon did not come as a result of a possible local army intention of a general move to the smaller caliber, but rather of an in-house study that showed that this might be a trend in the future. Official interest eventually came in the form of a Brazilian Army Staff document of 1986 (Objetivos Básicos Operacionais 39/86, Basic Operational Targets 39/86) which stated that a 5.56x45mm rifle would be needed as the basic weapon for the 1 Batalhão de Operações Especiais (1st Special Operations Battalion) that had been created three years earlier. However, the unit’s reduced size of about 600 men at that time meant that a possible Army purchase would be comparatively small and would not justify the considerable R&D costs involved in creating an entirely new weapon.

With the obvious goal of reducing development time and costs, however, IMBEL’s management later modified its objective. Instead of developing a rifle using some M964/M964A1 components, it was decided to go ahead and build a whole FAL in 5.56x45mm, and this included the use of the original tilting block breech locking system. In fact, virtually all tooling and basic reference drawings for the 7.62x51mm model could be used with little or no changes. A prototype of the new rifle was completed in 1985, and this employed the well-known tubular folding stock the of the so-called “PARA” version of the FAL. No thermal protection was provided for the gas cylinder nor for most of the weapon’s barrel, but a short wooden handguard taken from the heavy-barrel version (squad automatic weapon) of the Belgian gun was fitted. The dedicated 20-round magazine was kept, and this appeared to be the general way that the factory had chosen for the weapon’s evolution.

A major evolutionary step came in the form of the MD97 models which featured a rotary-bolt breech locking system and a light-allow receiver. The selective-fire MD97L rifle (437 mm barrel) was supplied in limited numbers to the Brazilian Army for field evaluation purposes, while the semi-auto MD97LC carbine (330 mm barrel) was adopted by some state police agencies, including the Brasília-based Força Nacional de Segurança Pública (National Public Security Force).

Still keeping the original Fz 5.56 IMBEL MD1 designation, the gun was certified in April 1989 and cleared for production by the Brazilian Army as the M989, but it was not, in fact, officially adopted. Very small batches for demonstration and evaluation purposes were made, and these hardly differed from a PARA-FAL, featuring the very same foldable stock, synthetic handguard, pistol grip, trigger guard, knob-type cocking handle, sights, fire selector lever, flash hider, etc. With an optional foldable bipod fitted and a full 20-round magazine in place, the MD1 weighed 4.9 kg. One helluva heavyweight for a five-five-six!

The next evolutionary step took form in the early 1990s with the MD2/MD2A1 models (foldable stock, selective fire/semi-auto only) and the MD3/MD3A1 variants (fixed stock, selective fire/semi-auto only), but the initial market response made the FAL-type tubular folding stock the usual choice of operators. A rifle in this configuration was officially tested at the Campo de Provas da Marambaia (Marambaia Proving Grounds), in Rio de Janeiro, receiving its ReTEx – Relatório Técnico Experimental (Experimental Technical Report) No. 1364/91 on March 13, 1991, which cleared the way to production and sales. Following some local and foreign demonstrations, the MD2 received a number of orders, this including batches for some Brazilian Army BILs – Batalhões de Infantaria Leve (Light Infantry Battalions), while the semi-auto MD2A1 found its way into the armories of several state LE agencies, the Rio de Janeiro Public Security Department (Civil and Military Police) having purchased 1,050 examples in 1995, for example. As delivered, the rifles had a 453 mm barrel, an overall length of 1030 mm (764 mm, with the stock folded), and a loaded (30 rounds) weight of 4.85 kg, still a hefty gun for the caliber. At this point, however, STANAG-compatible magazines were used rather than the earlier dedicated type.

In 1995, the Brazilian Army issued Requisitos Operacionais Básicos (Basic Operational Requirements) No. 06/95 in which new parameters for a 5.56x45mm rifle were established, which included a 3.8 kg weight limit and a three-round burst facility. And things began to get better that year, when a young and enthusiastic Brazilian Army engineering officer, Captain (later Lieutenant Colonel) Paulo Augusto Capetti Porto, joined IMBEL. Some of his ideas began to take shape in the so-called MD97 family, with members available both in rifle (MD97L) and semi-auto carbine (MD97LC) versions. The latter eventually received a substantial order for 3,000+ copies to equip the Força Nacional de Segurança Pública (National Public Security Force), a nationwide LE agency with headquarters in Brasília, the nation’s capital, which deploys whenever and wherever an emergency situation arises in any state. Series manufacture of the MD97LC carbine began in 2004, while a small batch of selective-fire MD97L rifles was handed over to the Brazilian Army for troop evaluation. This was carried out by the CAEx – Centro de Avaliação do Exército (Army Evaluation Center) and by some units, such as the Bda Op Esp – Brigada de Operações Especiais (Special Operations Brigade). Evaluation tests were also carried out by the Air Force and the Navy/Marine Corps, but no orders were received.

This particular example of the semi-auto IA2, photographed in April 2015, displays a number of changes, such as a much-redesigned foldable buttstock (adjustable in length), a hand support forward of the magazine housing, and a duplicated fire-selector lever on the right side.

The main design improvement in the MD97s was the use of a rotary bolt whose radial lugs locked directly to a barrel extension rather than to the lower receiver, as required by the FAL tilting block, permitting the use of light alloy materials in the somewhat redesigned lower. This resulted in some weight saving, the MD97LC carbine coming down to reasonable 3.3 kg, empty, while the rifle was 0.3 kg heavier. The cold-hammered, chrome-plated 330 mm (440 mm, for the MD97L rifle) barrel was rifled with a 1:10 in (1:254 mm) pitch so that both M193 and SS109 rounds could be fired with adequate ballistic performance. Respective muzzle velocities were 840 and 920 m/s. Barrel life was officially quoted as being over 5,000 rounds fired, but some prototypes eventually passed the 8,500 mark. Characteristic FAL components were still to be found here and there, including the pistol grip/trigger assembly, the foldable stock, and the handguard (shortened in LC carbine). Picatinny rails began to find their way to the top cover of the gun’s receiver, some of full length but most in the form of two in-line short units.

However, the MD97 family was still far from being what the Brazilian Army, the main potential client in view, wanted. While series production was under way to meet the Força Nacional and a few other local police forces orders, the design minds at the Itajubá Factory were not idle. Still under the strong leadership and personal participation of the head of the R&D Office, Captain Capetti, some interesting ideas turned into several working prototypes in 1997. They were generally designated FIL-97 (Fuzil Imbel Leve, Light Imbel Rifle) and FILC-97 (Fuzil Imbel Leve Curto, Short Light Imbel Rifle), a carbine-type variant.

This short foldable-stock FILC-97 prototype features a trigger guard for all the fingers of the firing hand, a short cylindrical handguard and a raised structure for, say, electro-optical sights. The weapon’s iron sights were used through openings in the so-called carry handle.

The initial selective-fire FIL-97 rifle, while keeping a FAL pistol grip/trigger assembly and the same handguard, introduced a new synthetic foldable stock, while a Picatinny rail was added to the top of the gun, which kept the original iron sights. More radical changes were found in a FILC-97 carbine variant of the same period. Although it presented a similar polymer right-side folding stock, a redesigned handguard of the same material was fitted, and this incorporated a rearward-folding foregrip. In addition to that, the gun featured a raised metal structure to accept optional optical sights, but the iron sights could still be used all the time thanks to the openings that existed on the front and rear ends of the, well, “carry handle”. Another distinguishing feature of that carbine was the pistol grip design that incorporated a full-size trigger guard that protected all the fingers of the firing hand.

Several other prototypes of both FIL and FILC variants incorporating varied ergonomic characteristics were made and tested at that time, and some are depicted in the accompanying photos. However, R&D funds were pretty much limited and did not allow full in-house development of a genuine IMBEL 5.56×45 assault rifle, a situation that was to persist for ten more years or so. In fact, it was only in 2008-2009 that the company appeared to seriously commit itself to the rifle program by adequately investing in personnel qualification and modernization of its production equipment. Emphasis was also placed on establishing comprehensive in-house test facilities, including environmental (sand, mud, water, hot/cold weather) conditions. All that had the aim of allowing the development and series manufacture of a rifle that would, at the very last, meet Brazilian Army’s ROB – Requisitos Operacionais Básicos (Basic Operational Requirements) and, at a later stage, Ministry of Defense’s ROC – Requisitos Operacionais Conjuntos (Joint Operational Requirements) for the three services, Army, Navy, and Air Force.

To all intents and purposes, the semi-auto IA2 seen here is the same selective-fire rifle called a “carbine” by IMBEL for internal marketing reasons. The all-black finish is typical for the weapons delivered to and in use by Brazilian LE agencies.

In mid-2010, some prototype photos and computer-generated images of the officially-called Fuzil de Assalto 5.56 IA2 began to emerge, complemented by the news that small batches were being completed for preliminary demonstrations and trials with the armed forces and law enforcement agencies. Pre-productions examples were fully displayed in April of the following year during the LAAD 2011 defense exhibition in Rio de Janeiro, these already incorporating visible modifications (notably, in the foldable polymer stock) from the earlier prototypes. On December 15, 2011, the Ministry of Defense issued Rule No. 3885-MD establishing the joint operational requirements for a common Fz Lv Cal 5.56 mm (Fuzil Leve Calibre 5.56 mm, or Light Rifle Caliber 5.56 mm) for the Brazilian Armed Forces. In 2012, extensive demonstrations of the semi-auto-only version of the rifle were carried out aiming at local police forces, while an initial production batch of 1,500 guns began to be delivered to the Brazilian Army for more comprehensive evaluation tests with 15 units in 11 different states. In October of that year, twenty IA2s were handed over to the Corpo de Fuzileiros Navais (Marine Corps) for the same purpose. A major breakthrough in the IMBEL rifle program was reached on October 23, 2013, when the Army issued Document No. 211-EME announcing the official adoption of the selective-fire rifle. Two thousand additional guns were delivered to the Army in 2014. In additional to these, the semi-auto IA2 has been adopted by a number of civil and military police forces, including those of the states of Bahia, Ceará, Espirito Santo, Minas Gerais, Pará, Paraíba, Piaui, Rio Grande do Norte, Rio Grande do Sul, Roraima, Santa Catarina, Sergipe, and São Paulo. In all, about 6,000 copies of both models had been made and delivered by December, 2014.

In its current form, the Fuzil de Assalto 5.56 IA2 operates with a pretty conventional gas piston/seven-lug rotary bolt system offering selective fire (semi-auto and full-auto, only) capability. For the record, the earliest versions were fitted with a three-round burst mechanism, but this was eventually omitted from the design as a result of extensive troop trials in the Amazon region having shown that this mechanical device was prone to malfunctions when used in severe environmental conditions. So, it seems that adequate troop fire training will prevail over extra gears, springs, and cams fitted inside the gun. Although featuring the same barrel length of 330 mm (350 mm, flash hider included), the semi-auto-only LE model is called by IMBEL Carabina 5.56 IA2, both models sharing the same dimensions and weights. The explanation appears to be that the local military authorities, whom the LE agencies depend on to get a green light for armament purchases, used to be somewhat reluctant to allow the police to buy “rifles”, but would generally agree to let them have “carbines”… The cold-forged steel barrel has four RH grooves and is rifled to 1:254mm (1:10 in). Overall and folded stock lengths are 850 and 600 mm, while the empty weight with the factory-made steel 30-round STANAG magazine is 3.6 kg (3.4 kg, no magazine fitted).

This FILC-97 light carbine prototype is fitted with the same folding stock of the rifle, but other details depart broadly from the FAL, as in the case of the pistol grip with a full-size trigger guard, the short handguard, the foldable vertical grip, and the raised structure for the fitting of optical/electronic sights.

As expected from any current weapon of its class, extensive use of polymers is found in the IA2, such as in the non-adjustable, right-side-folding stock, the pistol grip, and the three-piece handguard, where Picatinny rails can be added in the 3-, 6-, 9-, and 12-o’clock positions, in addition to the top receiver’s rail. The more-inclined FAL pistol grip for long used in all the earlier IMBEL 5.56×45 mm rifle attempts has given way to a redesigned model, its hollow being used for the storage of a cleaning kit. For the rifles being delivered to the Brazilian Army the polymer parts come in green, while those aimed at the local LE market are black. In fact, any color specified by a client can be provided by the manufacturer. Special attention was given to provide the handguard with adequate thermal protection, a problem that characterized the earlier MD97s which became very uncomfortable to hold after consecutively firing about six 30-round magazines in full-auto, when the hand contact zone reached about 54 degrees Celsius. New heat insulation materials used in the IA2 have reduced this to reasonable 38 degrees Celsius, with a slight temperature increase after firing 240 rounds in rock-and-roll. Water immersion tests have also shown the weapon to possess satisfactory functioning under most conditions, even being fired immediately after emerging, although at least five seconds of water drainage is recommended. Comprehensive environmental tests at extreme low (-40 degrees Celsius during four hours) and high temperatures, in addition to sand and mud exposure, have been successfully carried out. Preliminary rifle certification for the pilot batch was obtained on October 1, 2013, while that for the full technical and operational evaluation aspects, completed in December, 2014, are expected for early-2015.

Firing procedures with the IA2 are pretty straightforward. IMBEL has opted to supply the rifle with 30-round steel magazines of its manufacture for higher resistance and reliability, although any STANAG (AR-15/M16) model can be used. Magazine release from its well is achieved either by pressing inwards a protected button located on the right side at the junction of the upper and lower receivers or by pressing forward a lever at the rear of the magazine housing. The cocking knob, an FAL type, is on the left side and does not reciprocate when the gun is fired. If you are a right-handed shooter, you’ll find the fire selector lever conveniently located on the left side within easy reach of your thumb, immediately above the pistol grip. Some guns, however, have been fitted with a selector lever duplicated on the right side, apparently, a Brazilian Navy/Marine Corps requirement for a future purchase. Settings are “S” (Safety), up; “I” (Intermittent, or Semi-auto), slightly down; and, not available in the LE carbine, “A” (Automatic), slightly under 180 degrees, forward. Cyclic rate of fire is around 750 rounds per minute. The rifle version comes with a bayonet lug where IMBEL’s FC-IA2 (178 mm blade) or FC-Amz (247 mm blade) bayonet knives can be attached.

Seen here in the hands of Rio de Janeiro Military Police troopers in training, the MD2A1 shifted to the use of STANAG-type 30-round magazines, while still keeping the FAL tilting-block breech locking system.
A brand-new IMBEL IA2 rifle in the hands of a Brazilian Army Parachutist Infantry Brigade officer, the weapon’s polymer components green color having been a choice of that service.