This was written by Ronaldo Olive and originally published in Jane’s Defense Weekly in 1984, when the LAPA FA-03 was still more or less in prototype phase – bullpup rifles have become more widely accepted since then. Unfortunately for LAPA, the Modelo 03 was not accepted for military use, and no foreign orders were¬†received – only this single prototype was ever built. So without further ado, read on about this Brazilian combat rifle with some interesting features. Thanks, Ronaldo!

Brazilian 5.56mm LAPA Assault Rifle Reaches Official Testing Phase

by Ronaldo Olive

The appearance of yet another 5.56mm assault rifle on the military scene may not attract much attention, unless it has the now fashionable bullpup configuration, which gives it an increased chance of receiving more than just a casual glance. And if this rifle incorporates novel and mainly useful features, then it deserves a thorough examination. This is the case of the LAPA FA Modelo 03, a newcomer to the small-caliber rifle arena, which is about to start official certification testing at Campo de Provas de Marambaia (Marambaia Proving Grounds), a branch of Brazil’s CTEx – Centro Tecnologico do Exercito (Army Technical Center). Janes Defense Weekly was recently given the chance to fire this new gun and to assess its general characteristics.

LAPA FA Modelo 03, left side

The FA (Fuzil Automatico, or Automatic Rifle) Modelo 03 was designed by LAPA – Laboratorio de Projectos de Armamento Automatico (Automatic Armament Design Laboratory), a Rio de Janeiro-based R&D concern. Initial work started at the end of 1978. After about a year, a technical feasibility prototype was completed, and its most promising characteristics led to additional prototypes to refine the design. Unavoidable snags were gradually removed and the Brazilian weapon has evolved into a working, reliable reality. Following certification, it is to enter production to meet local and foreign demand, but the company would not be specific about dates. Nor would is comment on reported approaches by foreign countries interested in licensed production agreements, but considering the hard competition in the arms business, its reticence in making some details public is understandable.


The rifle’s bullpup arrangement is the result of wishing to make it as compact as possible without shortening the barrel to a point where ballistic efficiency is degraded. So, the trigger is mover forward and the firing mechanism, together with the magazine, is fitted in the hollow of the buttstock.

LAPA FA Modelo 03, right side

The body of the LAPA FA Modelo 03 is built largely of high-impact plastic, has particularly elegant contours and is pleasant to handle and carry. A well-designed straight-line configuration has in fact resulted in the rifle being able to stand balanced on its buttplate! This has also dictated the raised sights configuration: the rear sight, a two-position (200m and 400m) flip aperture, is housed within the AR-10 style carrying handle, while the front sight is a protected post on top of a stury raised metal frame at the muzzle. Radius is a generous (for the bullpup configuration) 374mm (14.7 inches). The cocking handle, which remains stationary when the gun is fired, is within the carrying handle, and the top end runs along a slot on the underside of the handle, giving it more rigidity.

LAPA FA Modelo 03 top view


At present, the gun is chambered for the 5.56x45mm M193 ball-type cartridge, the 490mm (19.3 inch) barrel having six-groove rifling with a pitch of one turn in 305mm (1:12 inch). Production examples, as expected, will also be barreled for the newer SS109 NATO round. A flash hider is fitted to the muzzle, and a bayonet attachment is provided. Feed is from 20- or 30-round M16-type metal box magazines in the prototype, but production gun are likely to use curved 20-, 30-, or 40-round plastic magazines. The magazine is inserted upwards into its guide inside the stock, and the catch at the rear is pressed forward to release the magazine. The ejection port, which can be set easily for right- or left-handed shooters, is fitted with a spring loaded cover that snaps open as the weapon is cocked or fired.

LAPA FA Modelo 03 magazine well

Firing Mechanism

The real innovations are those found in the firing mechanism. In place of the more conventional applied safety arrangements, the FA Modelo 03 has a double-action setting for the hammer, keeping it ready for immediate use, and at the same time protected from accidental firing. A single lever, on the left side of the stock between the magazine housing and the buttplate, is set for one of the three firing modes (“30” for full auto; “3” for controlled 3-round burst; “1” for semiautomatic fire) and the two action modes (“SA” for single action and “DA” for double action).

LAPA FA Modelo 03 selector lever

After or before cocking and feeding the weapons, which is done by pulling the cocking handle about 110mm (4.3 inches) backwards and releasing it, the shooter sets the fire-selector lever at one of the three fire positions. If fired immediately, the rifle will be set for single action, thus featuring a shorter and lighter trigger pull. After firing some rounds, or if no immediate use is anticipated, the lever can be turned to the “DA” mark and returned to one of the three fire positions. This will drop the hammer, allowing the gun to be carried in complete safety with a chambered round and ready for action: all that is needed is to pull the trigger (which will have a longer and heavier pull) to fire the rifle. If more accuracy is required for the first shot, the firer can move the lever to the “SA” marking and back to the chosen fire position, which will make the weapon fire the first round single-action. Operation is by gas, tapped from a port located about 160mm (6.3 inches) from the muzzle, which actuates an orthodox piston/rod assembly. Breech locking is achieved by the lugs of the rotating bolt.

LAPA FA Modelo 03 right rear view


Field stripping for routine cleaning is relatively simple requiring no tools. After removing the magazine and checking that the gun is unloaded, the buttplate pin is removed sideways to the right, which allows the buttplate together with the return spring and its guide to be pulled away and out of the stock. The takedown pin, aft of the pistol grip, is then removed from the weapon sideways to the right, separating the body into two halves. The lower half, which includes the magazine housing, pistol grip and the forward handguard, houses the firing mechanism, which becomes fully exposed for normal cleaning, no additional disassembly of this group being necessary. With the cocking handle pulled to the rear position, the top plastic cover can be removed, exposing the barrel/bolt assembly. The cap of the metal tubular receiver is unscrewed, and this allows the bolt and bolt carrier group to slide out. The gas rod and piston may then be removed. A reversed procedure is used to reassemble the weapon.

LAPA FA Modelo 03 with sling
LAPA FA Modelo 03 with sling

Shooting Impressions

Bullpup rifles are not easily found, especially in Brazil, so this was a first hands-on experience. Despite psychological preparation, the first impression is one of a “Star Wars” type weapon, even though the lines of the FA Modelo 03 are conservative if compared with, say, the Steyr AUG. After handling for a few minutes, however, and getting accustomed to the unusual magazine location, its compactness can be appreciated: only 735mm (28.9 inches) long, and with very smooth surfaces, in is “pleasant” to handle and carry, which is especially important for long marches, when the rifle is carried by the sling on one’s body. The forward sling attachment turns freely around the barrel, and coupled to a two-position (on/under the stock) rear attachment, it allows the rifle to be carried in various positions.

Author with the LAPA FA Modelo 03
Author with the LAPA FA Modelo 03

Firing from the Shoulder

Without its magazine, the prototype LAPA assault rifle weighs 3.2kg (7.0 pounds), though production weapons are expected to weigh 2.8kg (6.2 pounds). For aimed shoulder fire the sights are at a comfortable position for the eye. The spring-loaded rear sight flips to either 200m or 400m position easily, at the same time being rigid enough to not be displaced by accident. It is adjustable for windage, while the protected post front sight can be adjusted for elevation. The rear sight aperture is a little too small for quick target acquisition, but this is to be rectified in production weapons says LAPA.

LAPA FA Modelo 03 sights
LAPA FA Modelo 03 sights

The position of the cocking handle, on top of the gun, makes it ambidextrous, but because it has to be pulled with one or two fingers, the pull seems heavier when compared to a handle that can be held with thumb support. This is more than compensated for, however, by the handle remaining out of the way at all times.

The testing range was physically limited to about 50m, so long-distance accuracy was out of the question. Fired from the shoulder, the rifle is comfortable and provides a good rest for the firer’s cheek on the stock. Although the breech is closer to the ear than in conventional rifles there is no noticeable increase in noise level, though instrumented measurements may prove the contrary. The rifle’s straight-line configuration, with the barrel axis extending directly to the shoulder together with the very low recoil inherent to the 5.56mm ammunition, keeps the FA Modelo 03 rock-steady in semiautomatic fire. In this mode, fired standing, kneeling and prone, the gun handled well.

Author shooting the LAPA FA Modelo 03
Author shooting the LAPA FA Modelo 03

Controlled 3-round bursts were fired both from the shoulder and hip, the weapons always remaining very stable. The trigger has to be kept pulled for the duration of the burst. In this setting, if only one or two rounds are fired, the mechanism will reset automatically to be ready to fire three more times when the trigger is pulled again.

Automatic Fire

A great deal of automatic fire (at about 700 rounds/minute) was carried out, with the weapon held at hip height, assault style. Again, controllability was excellent, and the extreme compactness of the design, making the rifle only about 60mm (2.4 inches) longer than most stocked submachine guns, would be a definite bonus in close-in combat. Instinctive fire in multiple-target engagements, for instance, is greatly facilitated by the pistol grip being located almost halfway down the gun’s length, enabling quicker movements of the barrel at different targets. Single-handed shooting, with and without sling support, shows its remarkable balance and with a slight pressure between arm and body the rifle is kept steady even in full auto.

In photographs the ejection port may appear too close to the arm for comfort, however, in practice spent cartridges eject well away above and forward, not even the warmth of gases being felt by an unprotected arm, thus safety is in no way jeopardized.

LAPA FA Modelo 03 markings

Technical Specs

Caliber: 5.56mm
Cartridge: M193 55gr NATO 5.56x45mm
Rifling: Six groove, 1:12″ twist
Overall weight (empty): 3.2kg (7.0 pounds)
Overall length: 735mm (28.9 inches)
Barrel length: 490mm (19.3 inches)
Sights: Rear dual flip aperture (200m & 400m), front post
Sight radius: 374mm (14.7 inches)
Magazine capacity: 20- or 30-round (STANAG magazines)
Rate of fire: 700 rounds/minute


  1. The bayonet doesnt seam practical, but if they produce for civilians ill definately have to try one out.

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