The Brazilian LAPA SM Submachine Gun

By Ronaldo Olive

With the passing away of Nelmo Suzano on September 4, 2013, at the age of 83, blind and suffering from a number of health problems, one can’t help having some of those common “what if” thoughts come to mind. He was born in the Brazilian state of Espirito Santo, but lived most of his life in Rio de Janeiro, having joined Brazilian Army’s 8 Grupo de Artilharia de Costa Motorizado (8th Motorized Coastal Artillery Group) as a conscript in the late 1940s. While still in school, his copybooks were mainly covered with schematic drawings of firearms of all types based on his findings of rare technical publications he had managed to lay his hands on. His short, two-year stay in the Exército Brasileiro (Brazilian Army) was a long-awaited chance to have physical contact with the actual hardware. Not surprisingly, he soon joined his unit’s shooting team, later becoming a recognized champion.

In the early-1950s, after completing the compulsory military service period and spending most of his duty and free times taking guns apart and putting them together again, in addition to conducting repairs, he had become a proficient self-taught gunsmith. This was clearly recognized by the Brazilian Air Force Santa Cruz Air Base top brass, in Rio de Janeiro, who trusted him most of the maintenance work of its firearms, these including .45 ACP Colt M1911A1 pistols, selective-fire 7.63mm Mauser Schnellfeur pistols, .30 M1 and M2 carbines, .30-06 Garand and 7x57mm Mauser rifles. Of course, he also played a lot with .30-06 M1919 and .50 M2 Browning machine guns, the latter being the wing-mounted armament of the Santa Cruz-based Republic P-47D Thunderbolt fighters, for example.

In the mid-1950s, at the young age of slightly over 20, he joined his friend Olympio Vieira de Mello Filho (the future designer of the Uru submachine gun) to make superbly-finished custom hunting rifles, most of them in the so-called “African calibers” which they sold under the name “O.N. Gunmakers” to wealthy foreign and local hunters heading to Africa.

First SMG attempts

But, automatic weapons were, in fact, the main focus of Nelmo’s attention, and it didn’t take long for him to start working on his own designs. The earliest prototype, a dual-caliber (.45ACP and 9x19mm) delayed-blowback submachine gun came in the early 1960s, having never received a name, a designation, or reaching production status. Nor did he succeed in his second attempt, when a small concern called SOCIMARTE was established in Rio de Janeiro around 1971 to make a 9x19mm subgun designated SM9, which featured a magazine-in-pistol-grip configuration. This design was further improved the following year to become the BSM/9 M1 under the sponsorship of another Rio-based company, Bérgom S/A, which was tested and approved by the Brazilian Army at its Marambaia Proving Grounds. Even so, the design was again refined, and by 1974 a small pre-production batch was completed, still bearing the same designation, but featuring a number of internal and external improvements. In the years that followed, Nelmo Suzano ventured into several interesting SMG designs, each on its own deserving description in a detailed article, but the LAPA SM (from Sub Metralhadora, or Sub Machine gun) was chosen to represent his creativity.

The LAPA Company

After having worked somewhat independently for about three or four years, the designer came up with plans to build a family of guns employing polymer bodies, a 5.56x45mm bullpup rifle, a .22 LR select-fire carbine for LE use, a .22 LR carbine for sports use, and a 9x19mm submachine gun. Prototypes of these guns were built and means had to be found to series manufacture and market them, which led to the establishment in Rio de Janeiro in the early 1980s of a business concern to handle that: LAPA – Laboratório de Pesquisa de Armamento Automático Ltda. (Research Laboratory for Automatic Armament). Two other financing/administration partners – Army Gen. (retired) Fileto Pires Ferreira and Paulo Cochrane – joined Nelmo Suzano in the process.

An SM prototype had, in fact, been completed in 1978-79; its overall characteristics of reliability leading the newly-formed company to send it to Brazilian Army’s Campo de Provas da Marambaia (Marambaia Proving Grounds), in Rio de Janeiro, to be submitted to its tough certification test program so that it could be series manufactured and offered in the market. Official testing took place during most part of September, 1982, and the final certification document (ReTEx – Relatório Técnico Experimental No. 995) was issued on November 23, 1982. Nelmo’s subgun went through and passed an extensive range of working tests under extreme environmental conditions (rain, mud, sand, water, high and low temperatures), in addition to 6,500 rounds fired in the semi-auto and full-auto modes, safety tests (dropped on hard surfaces in different positions), resistance to over-pressure rounds, etc. All things considered, it seemed that LAPA had a great product in its hands with great sales potential.

But that was not to be the case. By 1984-85, the designer’s associates were somehow losing interest in the company and its products, even some letters and telex messages (it was, remember, a pre-internet era) asking for price and delivery quotations remaining unanswered. In 1987, he took his design to a newly-formed company called ENARM – Empresa Nacional de Armamento S.A. in Nova Friburgo, Rio de Janeiro State, but this was short-lived, though.

Technical Description

The SM operated on the pretty conventional blowback principle, firing from the open-bolt position with a fixed firing pin machined to the bolt head. All of its body was made of polymer (or high-resistant injected plastic material, as it was then called), divided into two main parts. The lower portion incorporated the butt stock, pistol grip, trigger guard, magazine housing and handguard, while the upper part included the AR-10 inspired rear sight structure protection (carrying handle) and the top side of the stock. A third synthetic component was the buttplate, which helped hold the other two elements together.

The receiver was tubular that projected well into the stock hollow, thus giving the cylindrical bolt a comparatively long (150 mm) rearward travel, reducing the cyclic rate of fire, and enhancing controllability. The two massive sight structures were directly attached to the receiver in an elevated position so that the weapon could boast a very straight line (barrel/bolt/buttplate) configuration. The rear sight, a flip-type (50-100 meters) aperture adjustable for windage, remained well protected within the carrying handle, while the front sight was a post adjustable for elevation and equally well protected by massive steel ears.

The cocking piece, with a rearward travel of about 85 mm, was centrally mounted within the handle and remained stationary in the forward position when the gun fired. The ejection port was on the right side and had a spring-loaded cover that snapped open when the weapon was cocked or the bolt moved forward. The magazine was inserted upwards into the housing located immediately ahead of the trigger guard. The original 30-round metal box magazines used by the prototype in the Army certification program were of the staggered-row, single-position feed type, but 32-round curved synthetic magazines with two-position feed were later made for the gun. The 15 mm long magazine catch blade was placed aft of the housing and was pressed forward to release the magazine from the gun.

The fire-selector lever was located on the left side, just above the pistol grip, positions being “S” (safety), to the rear; “30” (automatic), upward; and “1” (semi-auto), forward. The safety position, of course, blocked the trigger and the firing mechanism, and the gun possessed an additional safety item in the form of an internal inertia-type locking device that automatically blocked the bolt at its forward position in case the weapon was accidentally dropped or hit on the butt, thus preventing unintentional and hazardous firing. The bolt remained closed after the last round was fired.

Field-stripping the SM was a straightforward procedure, requiring no tools. The three metal pins that secured the body together (production guns would have only one) were first removed sideways to the right with the aid of a round of ammunition or any other pointed object. This allowed the buttplate to be pulled backward and detached from the stock. The body could then be separated into two halves, the bottom one exposing all of the firing mechanism for cleaning, making further disassembly unnecessary. The tubular metal receiver, with the integral sights structures, was then pulled away from the plastic cover/handle, this allowing the cocking piece and its rod to be detached from the bolt. The receiver could then be disassembled, which was done by unscrewing the rear cap, thus permitting the return spring and bolt to come out. The 202 mm long barrel (four grooves, RH, V at 5 meters: 410 m/s) was then removed from the forward end by unscrewing its mounting nut. This procedure took about two minutes, no hurry involved. Total disassembly would take some ten minutes, no hurry either, using just a pin pusher and flat-nose pliers. Total number of parts was 49; this including eight coil springs, four torsion springs, and two blade springs.

Handling and Firing

The SM immediately caught one’s eye because of its overall external appearance, much more so considering most of the subguns available in the market 30-or-so years ago. The smooth surfaces of the body made it pleasant to handle, and all firing procedures were self-evident. The close proximity of the magazine housing to the pistol grip was valued for contributing to fast ‘hand-finds-hand’ magazine changing procedures. The ambidextrous, centrally-mounted cocking handle was also valued. Although the position of the fire-selector lever on the left side meant that it was intended to be operated by the right thumb of a right-handed shooter, it just so happened that it was not exactly within reach, so one’s left hand could easily move it with a slight flip on the gun on its side.

The elevated sights (about 50 mm above the barrel axis) were quick and easy to use in acquiring targets at all distances, offering a radius of 290 mm. The gun’s overall in-line configuration meant that the firing recoil was directed straight to the shooter’s shoulder, aiding in more precise semi-auto fire and more controllable full-auto use. Cyclic rate of fire was in the region of 480-500 rounds per minute, a comfortable number for real-life, non-Hollywood use. Plus, it allowed one to squeeze out short (two or three round) bursts, and even single shots with the fire selector on the “30” mark. Trigger pull was 3.2 kg in semi-auto and 2.6 kg in automatic fire. The two-position aperture rear sight was somewhat on the smaller size, but this was expected to be dealt with in future production SMs.

The prototype weighed 3.4 kg with a full 30-round metal box magazine in place, but this was expected to go down to under 3 kg in production examples. With an overall length of 623 mm, it was the shortest fixed-stock submachine gun around at that time.

For sure, that modern-looking submachine gun designed by forward-looking Nelmo Suzano had all the characteristics that would lead to a successful commercial career. Like many other examples in the history of firearms, however, it somehow didn’t make it. Nelmo had previously tried a number of times. Then, later, he would try again. But that’s still to be told...

The Designation Enigma

Somewhat of a mystery has surrounded this gun as far as its designation is concerned. Although the single prototype was clearly marked as S.M.-MOD.3, the LAPA company and Nelmo Suzano himself called it the “02” and even mentioned to the author that future variations might include a MOD.02-A1 (hammer-fired, closed-bolt system), a MOD.02-A2 (double-action safety option), and a MOD.02-A3 (semi-auto only carbine version with a 16-inch barrel for the U.S. market). Also, it was persistently referred to as the LAPA SM Mod 02 in all Brazilian Army documents, including the final ReTex certification clearance, reproduced here.

This article first appeared in SmallArmsReview.com on January 10, 2014


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