Grossfuss MG - 42 The MG42 ( Abbreviation of German : " Maschinengewehr " 42 ) Is a gun chambered in Mauser 7 . 92x57mm developed during the WWII by Germany with the intention of replacing the MG - 34 With the manufacturing process simpler . His baptism of fire occurred in USSR and North Africa , Being a complete success . It was expected that she would replace the MG - 34 , but ended up supplementing it by not achieving the expected level of production . During the campaign of the FEB in Italy , the MG42 was nicknamed " Lurdinha " by GI ' s in Brazil due to the rapid rate of fire , reminiscent of the way to talk to the bride ' s jealous of one of them . In 1958 we developed a version of the MG42 for 7 . 62 mm ammunition , adopted as a standard by NATO . The new version was called MG42 / 59 or MG1 , Giving rise to variants MG2 and MG3 History . With adoption of the MG - 34 machine gun the Wehrmacht had the weapon that was envisaged some 20 years before , and the MG 34 bears the distinction of being the first practical universal ( or general purpose ) machine gun . While the MG - 34 was good and practical , it was certainly not ideal . German experts wanted their machine guns to fire faster , while being simpler and less costly . A high rate of fire was desirable both for AA applications and for surprise flanking fire against targets moving through the battlefield . As early as 1937 HWaA issued a request for the next new universal machine gun , and three companies received development contracts – Johannes Grossfuss AG , Stubgen AG and Rheinmetall - Borsig AG . In 1939 a commission selected the Grossfuss - made MG 39 prototype for further development . Designed by engineer Gruner ( often wrongfully referred to as Grunow ) and small arms designer Horn , new weapon , in accordance with HWaA request , had a stamped steel construction , combined with locked breech , short recoil action . Initial trials suggested that the Grossfuss MG needed further development , and in late 1941 a small batch ( about 1500 pieces ) of improved guns was manufactured for troop trials as the MG 39 / 41 . The new machine gun , while being made to lower standards of fit and finish , proved to be quite functional and reliable ( a feature that the much more “ refined ” MG - 34 lacked , especially in the mud and snow of the Russian front ) . Subsequently , it was officially adopted as the MG - 42 , and production commenced later the same year . In general terms , the MG - 42 was a great success . It fulfilled the roles of a light machine gun on a bipod , a medium machine gun ( on a newly developed Lafette 42 tripod ) , and an anti - aircraft machine gun , mounted in single and twin installations , ground and vehicle - mounted . It was relatively inexpensive to make and required less raw materials than the MG - 34 , and it was simple to maintain and use . On the minus side , it had a somewhat excessive rate of fire , usually quoted as 1200 rounds per minute , although German WWII era manuals listed it as 1500 rounds per minute ( 25 rounds per second ) . This rate of fire resulted in excessive consumption of ammunition and rapid overheating . While the extremely rapid barrel change procedure allowed for sustained fire , the resulting accuracy left something to be desired ; excessive vibration from recoil , combined with a short sight radius , resulted in degraded long range accuracy compared with earlier MG - 34 and , especially , the heavy Maxim MG - 08 guns . Nonetheless the MG - 42 was an impressive and fearsome weapon , known among Allied soldiers as “ Hitler ’ s saw ” , for the sound of the firing which resembled the sound of a giant mechanical saw . After the WWII this weapon , unlike other wartime designs , lived on , as in 1958 , the FRG ( West Germany ) re - instituted its official armed force , known as the Bundeswehr . Since the core of the Bundeswehr was formed of WWII veterans , it was logical to adopt weapons which were already proven and familiar to the troops ; and the MG - 42 was one of such weapons . It was , obviously , chambered for a ‘ non - NATO ’ cartridge , but this was only a minor issue , as the 7 . 62x51 NATO and 7 . 92x57 Mauser shared the same cartridge base diameter , and were somewhat similar in ballistics . The real problem , however , was that Germany had lost most manufacturing facilities for the MG - 42 , so the newly reestablished Rheinmetall concern had to install production facilities from the ground up . The production documentation for original MG - 42 machine guns was obtained from Grossfuss company and transferred to Rheinmetall ( German government had to pay significant royalties to Johannes Grossfuss for manufacturing rights ) . Since the preparation for manufacture took some time , the FRG purchased some ex - Wehrmacht MG - 42 weapons from other countries . Those guns were converted to 7 . 62 NATO by Rheinmetall and officially designated MG - 2 . The newly produced MG - 1 guns went through a number of modifications , which resulted in the definitive MG - 3 version , which still is rather close in design to the war - time MG - 42 , although made to much higher standards of fit and finish . The simplicity , low manufacturing cost and high effectiveness of the MG 3 attracted several other countries , which either bought the guns from Rheinmetall ( such as Denmark ) , or obtained manufacturing licenses and build ( or at least have built in the past ) the same guns domestically ( such as Italy , Iran , Turkey , Pakistan and Yugoslavia ) . In total , at least twenty armies have used or still are using the MG - 3 and its versions . It must be noted that in some countries these guns were used under their " commercial " Rheinmetall designation MG 42 / 59 . The MG - 42 is a short - recoil operated , air cooled , belt fed weapon which fires from an open bolt . The barrel is quick - removable , and can be replaced in less than six seconds by a properly trained crew , although an asbestos glove is required to remove the hot barrel . The action of the weapon is operated by the recoil of the locked barrel , assisted by a muzzle booster which uses pressure from the muzzle blast to increase the recoil impulse . Locking is achieved by a pair of rollers , which are forced outwards from the sides of the bolt head to engage cuts in the barrel extension . Locking ( outward ) movement of the rollers is controlled by the wedge - shaped front part of the bolt body ; unlocking ( inward ) movement of the rollers by the cams made in the receiver . This is a simple and solid system which minimizes the length of parts that are under stress upon discharge , and also minimizes the strain on the receiver . On MG 3 machine guns , two types of bolts are available , with standard weight ( about 650 gram ) for fast rate of fire and with heavy weight ( about 900 gram ) for slow rate of fire . It must be noted that those bolts also are used along with different return springs . The receiver and barrel jacket are made in one unit , and formed from a sheet of rolled steel , cut to shape by pressing and stamping , and then welded and pinned to form a gun housing of generally rectangular cross - section . The front part of the housing serves as a barrel jacket and has a number of oval cooling slots at all sides except the right . The right side of the jacket has one long slot which is used to remove the barrel . The barrel is held in place by a hinged lock , located at the rear of the opening in the right side of the jacket . To remove the barrel , the operator must first lock the bolt in the open position ( cock the weapon ) , and then turn the barrel lock to the right and forward . This will release the barrel and bring its breech area out of the jacket , so it can be grabbed ( using the issued asbestos glove or other heat insulation means if the barrel is hot ) and pulled back and out of the jacket . The new barrel is then inserted all the way forward and lock then is snapped into place , bringing the barrel into alignment with the action . The gun is fed using belts only . Feed direction is from the left to right ; the feed is of the one - stage , push - through type . The belt is same as for the MG - 34 , with steel links with open pockets , assembled into non - disintegrating 50 - round lengths . The same MG - 34 type “ Gurttrommel ” 50 - round drum - type belt containers can be used with the MG - 42 , and a new type of lightweight plastic 50 - round belt container was developed in West Germany by HK and is now issued with MG - 3 guns . The belt feed is operated by the reciprocating bolt which has a roller at the top of its body . This roller engages the cam track in the oscillating lever , located in the top - opening feed cover . The lever operates the belt pawls in two steps , on both opening and closing movement of the bolt , resulting in a smooth and positive feed . This two - step belt traction is particularly useful because the high rate of fire results in high - speed belt movement , and this system reduces the strain put on both the feed unit and belt links . Current production MG - 3 guns can fire either non - disintegrating or disintegrating belts . The trigger unit is of relatively simple design , and permits for automatic fire only . The manual safety is of the cross - bolt , push button type , located at the top of the pistol grip . The charging handle is located at the right side of the receiver , and is separated from the bolt group ( it does not move when gun is fired ) . Each MG - 42 was issued with an integral , adjustable bipod attached near the muzzle ; MG - 3 guns may have two points for bipod attachment , one near muzzle and another near the center of the gun . In the medium role , the MG - 42 was used from the Lafette 42 , a complicated foldable tripod with buffered cradle . A wide number of tripods is available for MG - 3 guns , as produced in several countries . The standard sights are open , fully adjustable , and mounted on folding bases . The universal tripod has provisions for mounting telescopic sights for long range and indirect fire missions . Outside of NATO :