The IMBEL MD97 is a Brazilian made automatic assault rifle developed for both military and security use and has its indirect origins in the excellent Belgium made FN FAL light automatic rifle. Directly, the MD97 is based on the IMBEL MD2 series, the standard-issue assault rifle of the Brazilian Army inducted in 1985. The MD97 exists in three major variants made up of the MD97L (L for "leve" or "light") standard assault rifle with selective fire, the specialized MD97LM with attachment rails (MIL-STD-1913) meant for special forces use and the MD97LC, a shortened carbine version of the base MD97L restricted to semi-automatic fire and suitable for heavy duty police force work. The three are more or less differentiated from one another through their varying weights and overall dimensions. The MD97 entered service in 1997 intending to replace the IMBEL MD-2 and MD-3 series rifles and remains an important weapon in the Brazilian arsenals. The MD97 shares more in common with the MD-2.
At its core, the MD97 sports a design not unlike the FN FAL itself. She fires the 5.56x45mm NATO standard cartridge from a 20- or 30-round STANAG type (M16 style) curved magazine. Depending on the model, her rate-of-fire is listed at 950 rounds per minute with a muzzle velocity of 950 meters per second. The firing action is gas operation utilizing a rotating bolt. Her effective range is out to 600 meters while her maximum range reaches 3,800 meters. Weight of the base MD97 is 3.7 kilograms while the shortened and lighter MD97LC is 3.3 kilograms. Her overall length is listed at 850mm, 437mm of this made up of the barrel. The barrel itself is noted as having a relatively short operational life of just 6,000 rounds. The MD97L features single-, burst- and full-automatic fire modes and is the only system of the three MD97 rifles to accept an underslung single-shot grenade launcher attachment. Additional optics, flashlights and sound suppressors are optional.
The receiver contains the internal operational aspects of the rifle including the pistol grip, trigger group and magazine feed. The charging handle is set to the right hand side of the body. The buttstock can be solid or skeletal with the latter form being able to fold down over the side of the receiver, making for an even more compact weapon system. There is a vented foregrip over the rear portion of the barrel with the barrel extended out some ways from the design, capped by a vented muzzle brake. Sights are featured at the extreme forward and rear ends of the weapon as do shoulder sling mounts.
IMBEL is the marked producer of the MD97 family. The letters serve as an acronym for Brazil's state-run Industria de Material Belico do Brasil. The institution was started in 1975. It is suspected that the German made Heckler & Koch HK G36C carbine might replace the MD97 in the long run, a proven weapon that does not feature as many prominent limitations as the IMBEL design.