Assault Rifle The Assault Rifle is a lightweight , selective - fire weapon that is currently being used by all armies in the world , the assault rifles can be made in two configurations : Classic ( weapons like AK - 47 ) and the bullpup ( weapons like the FAMAS ) History . Assault rifles are primary offensive weapons of modern troops . Today ' s AR ( Assault Rifles ) usually have calibers ranging from 5 . 45mm to 7 . 62mm , magazine capacity of 20 - 30 or more rounds , selective full auto and single shot modes of fire , plus , in some models , 2 or 3 round burst mode . Effective range of fire is some 600 meters or so ; effective rate of fire - up to 400 - 500 rounds per minute in full auto mode . Many assault rifles shown here are , in fact , parts of whole families of assault firearms ( from short carbines to light machineguns - Steyr AUG and AK - 47 ) are good examples ) . Almost all AR ' s may be equipped with bayonet , optical or Night Vision scope / sight and , some of them , with underbarrel grenade launcher or rifle grenade launcher ( rifle grenades usually are put on the barrel and fired with a blank cartridge ) . Today ' s trends in AR design are wide usage of hardened plastics and lightweight alloys and built - in holographic ( collimator ) or optical scopes with magnitfication of 1X to 4 - 6X ( usually 1X or 1 . 5 - 3X ) . Most of the worlds ' recent assault rifles are designed in bull - pup configuration . This means that buttplate is attached directly to the receiver and handle with the trigger placed ahead of the magazine veil . The only major countries that still stick to conventional AR design are Germany ( their latest G - 36 looks a little bit more ' conservative ' , comparing to Austrian AUG or latest Israeli Tavor ) , Russia , where latest ARs are developed in both ' classic ' ( AN - 94 , AK - 10x ) and ' bull - pup ' ( Groza OC - 14 ) styles and EUA , witch uses the Colt M4 and the M16 . The history of the concept of the assault rifle started in the early 1910s , when the famous Russian armorer , col . Fedorov designed a small - bore selective - fire rifle with detachable box magazine . Initially , Fedorov designed a brand new small - caliber 6 . 5mm cartridge for his rifle , but , due to WW1 , switched to the Japanese 6 . 5mm Arisaka load , which was less powerful than the Russian 7 . 62x54R and available in quantity . This rifle was acquired by the Russian army in small numbers in 1916 and served ( in very limited quantities though ) with the Russian and Soviet ( Red ) Army up to 1925 . While the design of the selective - fire rifle was not unique for that time , the concept of the " lightened " cartridge , more suitable for full - auto fire , was new . Also , col . Fedorov invented the idea of infantry weapons families ( assault rifle , light machinegun , medium machinegun , vehicle and / or aircraft mounted MGs ) based on the same actions and receivers . The next step in this history was made by Germany - in the 1930s , theybegan research to develop a medium - power cartridge , which would be much lighter than 7 . 92mm German and easier to fire accurately in full - auto mode . This development led to the 7 . 92x33mm cartridge ( Pistolenpatrone 7 . 92mm ) . The Germans developed some weapons designs for this load , including the MP43 and Stg . 44 , but this was too late for Germany . . . Further development of such designs was made by German engineers in Spain , and later in West Germany , and led to the HK G3 / G41 family of battle & assault rifles . The United States also put in some effort to this idea , and before WW2 developed a special less - than - medium powered cartridge . 30Carbine and a rifle for this cartridge - a so - called " baby - Garand " in semi - auto M1 and selective - fire M2 . But the largest stride forward was made by the USSR , when , in 1943 , the Soviet Army adopted a new cartridge - the 7 . 62x39mm medium - power load . In 1945 , the Soviet Army adopted the semi - auto SKS rifle in this chambering , and , in 1947 - the AK ( known for the West as AK - 47 ) . The AK was Worlds ' first successful assault rifle , and one of the most widely used . The Last major step on this road was made by US again - in the late 1950s , the US Army adopted a new ( for the US ) concept of military selective - fire rifle using a small - caliber cartridge . The first of , the most well - known assault rifle in the world , he and his variants are being used even today around all world ] ] such weapons adopted was the Armalite AR15 / Colt M16 , designed by Eugene Stoner . This adoption lately set the new world trend for small - caliber ( 5 . 45 - 5 . 56mm / . 22in . ) high - velocity cartridges . All further research and development , such as caseless ammunition , multiple - bullet or sabot cartridges , etc . , still haven ' t produced any practical results . Future . Small arms technology including the assault rifle can be described as a mature technology . However , changes in battlefield realities can be expected to lead to technological changes . As weapons evolve , the delicate balance for assault rifle systems between power , weight , recoil and terminal effects will likely shift once again in an attempt to defeat body armour , to match the range of full - power cartridges , and to penetrate through wind shields and thin - skinned vehicles while still producing good terminal effects . Possible future directions are armour piercing or saboted sub - caliber tungsten darts , more powerful cartridges , application of new composite materials such as carbon fiber or carbon nanotubes , and use of exotic metals such as titanium and scandium . As personal body armour technology improves , for example from the development of Magnetorheological fluid - based smart materials , assault rifle designs will be forced to adapt in order to remain effective . Changes in assault rifle technology may come from maturation of other fields - as camera technology becomes more advanced , cameras may be integrated into rifles . Much research and development has already been put into integration of rifles with advanced electronics . The FN SCAR . The future of the assault rifle may not be entirely in the design of the firearm itself , but rather in the ammunition it fires . Reducing weight and cost being one of the original reasons for the development of the intermediate powered round and subsequently the assault rifle , that goal has been taken to a whole new level with the development of caseless ammunition which does away with the weight and cost of shell casings . Limitations of current technology prevent this idea from being successful but the concept is still being researched . Recent progress with the light weight small arms technology program has made the concept of caseless ammunition a step closer to reality .