IMBEL MD - 97 The IMBEL MD - 97 family of rifles was developed on the basis of earlier IMBEL MD - 2 rifles , with certain improvements in parts and overall size . The family consists of two basic models , the selectively - fired MD - 97L rifle , which is intended for Brazilian Army ' s Special Forces , and semi - automatic only MD - 97LC carbine , which is intended for police use . IMBEL MD - 97 rifles feature gas operated action with short - stroke piston and rotary bolt locking . The trigger unit and folding or fixed buttstock are same as on earlier 7 , 62mm Fz MD963 rifles ( Brazilian - made copies of Belgian FN FAL rifle ) . Both rifle and police carbine variants are available with either fixed or folding buttstocks ; the military MD - 97L also can be fitted with domestically - made 40mm underbarrel grenade launcher or bayonet . MD - 97 rifles use M16 - compatible magazines . Description . The new assault rifle Imbel MD97 , is the result of a need demonstrated by the Brazilian army in providing their infant with a new and modern weapon in caliber 223 or 5 . 56 x 45mm . In the early adoption of such studies for a smaller caliber , Imbel made some adjustments to his already established , the FAL rifle could shoot 5 . 56 mm ammunition . However , the changes were extremely basic , involving the replacement of the barrel chamber and recalibration and adjustment of the springs . What we had was a gun that worked on the same system of operation of the SCA , tilting bolt . This new weapon is called MD - 2 , which had folding butt ( For Fal ) , and MD - 3 for the version with fixed butt . These weapons , although reliable , failed to meet an important requirement for the army , which was the need for them to be lighter than the heavy FAL , which has always represented a sacrifice for the soldiers on long marches . To solve this , Imbel realized it would need to build a new weapon system with different and lighter than MD2 . After researching and analyzing costs , reached a conclusion to take advantage of those parts of the PA that would not add more weight to the new project and still maintain production at a low cost enabling a competitive market value , between similar weapons . Some design prototypes with more " exotic " were tested , but the end result was a weapon that looked like a FAL slightly shorter and more " skinny " . The new weapons had made a new system of rotating bolt , bolt instead of tilting the FAL , and it allowed him to retain only those parts directly related to the process of shooting , such as pipe and steel bolt , which is heavier . Thus , the frame of the rifle could be made of a material lighter than steel FAL necessary for the locking bolt tumbler , which took place in the structure of the weapon . The new material was a special aluminum alloy ( ASTM 7075 ) to meet the weight requirement . Otherwise , the new weapon , has also another feature that was requested by the Brazilian Army , the ability to short bursts or burst , which are short bursts of three shots ( there are other weapons in bursts of two shots ) . This ability is very useful to avoid wasting ammunition when the soldier is in the midst of a battle where the tension could cause it to shoot more than necessary shots and running out of ammo , which is the last thing you ' ll want to spend an infant , during a fight . These new rifles were sent to field test Marambaia , which passed a comprehensive test for fire resistance and were approved . The newly formed " National Security Force " was the first government unit to be equipped with a carbine version of this rifle which is the short version . Many police institutions in Brazil , too , are being equipped with this new weapon . Now just wait for the release of more funds for the army be able to acquire this modern weapon for their infants and thus modernize its troops with a domestic product and with the already known high quality of products Imbel .