An autocannon or automatic cannon is a large automatic, rapid-fire projectile weapon that fires armour-piercing or explosive shells, as opposed to the bullet fired by a machine gun. Autocannons have a larger calibre than a machine gun, but are smaller than a field gun or other artillery; when used on its own, the word "autocannon" indicates a single-barrel weapon. When multiple rotating barrels are involved, the word "rotary" is added, such a weapon is referred to as a "rotary autocannon". Modern autocannons are not single soldier-portable or stand-alone units, rather they are vehicle-mounted, aircraft-mounted, or boat-mounted, or remote-operated as in some naval applications; as such, ammunition is fed from a belt to reduce reloading or for a faster rate of fire, but a magazine remains an option. They can use a variety of ammunition: common shells include high-explosive dual-purpose types, any variety of armour-piercing types, such as composite rigid or discarding sabot types. Although capable of generating a high rate of fire, autocannons overheat if used for sustained fire, are limited by the amount of ammunition that can be carried by the weapons systems mounting them.
Both the US 25 mm Bushmaster and the British 30 mm Rarden have slow rates of fire so as not to use ammunition too quickly. The rate of fire of a modern autocannon ranges from 90 rounds per minute, to 2,500 rounds per minute with the GIAT 30. Systems with multiple barrels can have rates of fire of over 10,000 rounds per minute; such high rates of fire are employed by aircraft in air-to-air combat and close air support attacks on ground targets, where the target dwell time is short and weapons are operated in brief bursts. The first modern autocannon was the British QF 1 pounder known as the "pom-pom"; this was an upscaled version of the Maxim gun, the first successful automatic machine gun, requiring no outside stimulus in its firing cycle other than holding the trigger. The pom-pom fired 1 pound gunpowder-filled explosive shells at a rate of over 200 rounds a minute: much faster than conventional artillery while possessing a much longer range and more firepower than the infantry rifle. In 1913, Reinhold Becker and his Stahlwerke Becker firm designed the 20mm Becker cannon for the German Empire's perceived need for heavy-calibre aircraft armament, was assisted by the Imperial Government's Spandau Arsenal in perfecting the ordnance - although only about 500+ examples of the original Becker design were made during World War I, the design's patent was acquired by the Swiss Oerlikon Contraves firm in 1924, with the Third Reich's Ikaria-Werke firm of Berlin using Oerlikon design patents in creating the MG FF wingmount cannon ordnance, in Imperial Japan, their navy's adoption and production of the Type 99 cannon in 1939 was based on the Becker/Oerlikon design's principles.
During the First World War, autocannons were used in the trenches as an anti-aircraft gun. The British used pom-pom guns as part of their air defences to counter the German Zeppelin airships that made regular bombing raids on London, but they were of little value, as their shells neither ignited the hydrogen of the Zeppelins, nor caused sufficient loss of gas to bring them down. Attempts to use them in aircraft failed as the weight limited both speed and altitude, thus making successful interception impossible; the more effective QF 2 pounder naval gun would be developed during the war to serve as an anti-aircraft and close range defensive weapon for naval vessels. Autocannons would serve in a much greater capacity during the Second World War. During the inter-war years, aircraft underwent an evolution and the all-metal monoplane, pioneered as far back as the end of 1915 replaced wood and fabric biplanes; the subsequent increase in speed and durability reduced the window of opportunity for defence.
Heavier anti-aircraft cannon had difficulty tracking fast-moving aircraft and were unable to judge altitude or distance, while machine guns possessed insufficient range and firepower to bring down aircraft consistently. Weapons such as the Oerlikon 20 mm and the Bofors 40 mm would see widespread use by both sides during the second World War. Continued ineffectiveness against aircraft despite the large numbers installed during the second World War led, in the West, to the removal of all shipboard anti-aircraft weapons in the early post-war period; this was only reversed with the introduction of computer-controlled systems. The German Panzer II light tank, one of the most numerous in German service during the invasion of Poland and the campaign in France, used a 20 mm autocannon as its main armament. Although ineffective against tank armour during the early years of the war, the cannon was effective against light-skinned vehicles as well as infantry and was used by armoured cars. Larger examples, such as the 40 mm Vickers S, were mounted in ground attack aircraft to serve as an anti-tank weapon, a role to which they were suited as tank armour is lightest on top.
Polish 20 mm. Unlike the Oerlikon, it was effective against all the tanks fielded in 1939 because it was built as an upgrade to the Oerlikon, Hispano—Suiza, Madsen. It, with great difficulty, proved capable of knocking out early Panzer IIIs and IVs. Only 55 were produced by the time of the Polish Defensive War. In airc
Mountain guns are artillery pieces designed for use in mountain warfare and areas where usual wheeled transport is not possible. They are similar to infantry support guns, are capable of being broken down into smaller loads. Due to their ability to be broken down into smaller "packages", they are sometimes called pack guns or pack howitzers. During the American Civil War these small portable guns were used and were called "mountain howitzers." The first designs of modern breechloading mountain guns with recoil control and able to be broken down and reassembled into efficient units were made by two Greek army engineers, P. Lykoudis and Panagiotis Danglis in the 1890s. Mountain guns are outdated, their role being filled by mortars, multiple rocket launchers, recoilless rifles and missiles. Most modern artillery is manufactured from light-weight materials and can be transported assembled by helicopters. List of mountain artillery Popular Science, May 1941, "The Old Army Army Mule Takes Guns Where Wheels Won't Go" Assembling the Howitzer detail photos showing a 75mm howitzer's various sections being taken off mules and assembled
Royal Garrison Artillery
The Royal Garrison Artillery was formed in 1899 as a distinct arm of the British Army's Royal Regiment of Artillery serving alongside the other two arms of the Regiment, the Royal Field Artillery and the Royal Horse Artillery. The RGA were the'technical' branch of the Royal Artillery who were responsible for much of the professionalisation of technical gunnery, to occur during the First World War, it was established to man the guns of the British Empire's forts and fortresses, including coastal artillery batteries, the heavy gun batteries attached to each infantry division and the guns of the siege artillery. The RGA was amalgamated with the RFA in 1924, from when the only two arms within the Royal Regiment of Artillery are the Royal Artillery and the Royal Horse Artillery; the Royal Garrison Artillery came into existence as a separate entity when existing coastal defence, mountain and heavy batteries of the Royal Artillery were amalgamated into a new sub-branch. A royal warrant provided that from 1 June 1899: "... the mounted and dismounted branches of the Royal Regiment of Artillery shall be separated into two corps... to be named the Royal Horse Artillery and the Royal Field Artillery: the Royal Garrison Artillery."
The Royal Regiment of Artillery, was divided into four branches. Other than mounted or unmounted dress, the obvious distinction in uniform was by the shoulder title badges: RGA. Non-regular Royal Garrison Artillery units in Great Britain were found from Artillery Volunteer units, many of which were styled Royal Garrison Artillery after 1902; the Militia Artillery were re-titled in 1902 becoming Royal Garrison Artillery. After the formation of the Territorial Force in 1908, a number of RGA Volunteer units were styled Defended Ports units and were incorporated into the RGA, they were allocated to the defence of ports around Great BritainThe RGA retained the badge and dress uniform of the Royal Regiment of Artillery, but personnel were clothed and equipped as dismounted men. After 1920 all RGA personnel were classified as mounted men, whether serving in horse-drawn, mountain or tractor-drawn batteries, Fixed artillery was placed in forts and batteries in locations where they might protect potential targets from attack, or from where they might prevent the advance of an enemy.
This included forts and batteries intended to protect against military forces on the land, against naval forces on the sea. Coastal artillery relied on high velocity guns, capable of striking out at ships at a great distance, penetrating their armour. Inland defensive batteries might have armament better suited for use against personnel. Mobile artillery pieces were sometimes used that could be re-deployed as required between fortifications that were not permanently manned or armed. Fixed batteries were operated in the early 20th Century by the RGA, including its Militia Artillery and Volunteer Force reservists. Conventional wisdom held that a naval force would need a three-to-one advantage over coastal artillery, as the land-based artillery had the advantage of firing from a fixed platform, with resultant advantages in accuracy as range increased. By the start of the 20th century, the increasing size of the capital ships of the world's largest navies, of the guns they wielded, was sounding the death knell of coastal artillery.
As the primary armament of battleships and battle-cruisers reached 16 inches, while coastal artillery was 6 inch or 9 inch guns, a large naval force, including capital ships, could level coastal batteries from a range that kept them out of reach of answering fire. The advent of artillery had changed the design of fortifications centuries before, spelling the end of high-walled castles. By the 20th century, fortifications were being designed with as much surrounding embankment by earthworks as possible. While this provided some protection from direct fire, it made defence against infantry more difficult, did nothing to protect from high trajectory fire landing from above, or from air-bursting explosive shells, which rained the area enclosed by walls with shrapnel. In Bermuda, in the latter part of the 19th Century, where the War Office had expended vast fortunes building up fortifications to protect the Royal Naval Dockyard, it was decided belatedly that the Dockyard's own fleet of naval vessels could provide a more effective defence.
With the advent of the aeroplane, the missile, fixed artillery was both obsolete and too vulnerable to continue in use. The last coastal artillery was removed from use in the 1950s; the emerging need for air defence of the United Kingdom was discussed between the Admiralty and the War Office prior to the outbreak of the First World War. In August 1914 the responsibility was still split, with the Royal Garrison Artillery employing 30 officers and 312 men on air defence duties. By February 1916 the Army had entire responsibility for the air defence of the United Kingdom. In May 1916 56 Companies of the RGA were created to command the guns. By November 1917 639 officers and 8,436 men of the RGA were manning anti-aircraft defences, as well as 4,309 men of the Royal Engineers and 424 men of the Army Service Corps; the mountain batteries of the Royal Artillery were incorporated within the Royal Garrison Artillery during its existence. In 1918 there were 20 batteries which all served in India, Palestin
Naval artillery in the Age of Sail
Naval artillery in the Age of Sail encompasses the period of 1571–1862: when large, sail-powered wooden naval warships dominated the high seas, mounting a bewildering variety of different types and sizes of cannon as their main armament. By modern standards, these cannon were inefficient, difficult to load, short ranged; these characteristics, along with the handling and seamanship of the ships that mounted them, defined the environment in which the naval tactics in the Age of Sail developed. Firing a naval cannon required a great amount of labour and manpower; the propellant was gunpowder, whose bulk had to be kept in the magazine, a special storage area below deck for safety. Powder boys 10–14 years old, were enlisted to run powder from the magazine up to the gun decks of a vessel as required. A typical firing procedure follows. A wet swab was used to mop out the interior of the barrel, extinguishing any embers from a previous firing which might set off the next charge of gunpowder prematurely.
Gunpowder was placed in the barrel, either loose or in a cloth or parchment cartridge pierced by a metal'pricker' through the touch hole, followed by a cloth wad rammed home with a rammer. Next the shot was rammed in, followed by another wad to prevent the cannonball from rolling out of the barrel if the muzzle was depressed; the gun in its carriage was then'run out'. This took the majority of the gun crew manpower, as the weight of a large cannon in its carriage could total over two tons, the ship would be rolling; the touch hole in the rear of the cannon was primed with finer gunpowder or from a quill pre-filled with priming powder ignited. The earlier method of firing a cannon was to apply a linstock—a wooden staff holding a length of smoldering match at the end—to the touch-hole of the gun; this was dangerous and made accurate shooting difficult from a moving ship, as the gun had to be fired from the side to avoid its recoil, there was a noticeable delay between the application of the linstock and the gun firing.
In 1745, the British began using gunlocks. The gunlock, by contrast, was lanyard; the gun-captain could stand behind the gun, safely beyond its range of recoil, sight along the barrel, firing when the roll of the ship lined the gun up with the enemy, so reduce the chance of the shot hitting the sea or flying high over the enemy's deck. Despite their advantages, gunlocks spread as they could not be retrofitted to older guns; the British adopted them faster than the French, who had still not adopted them by the time of the Battle of Trafalgar, placing them at a disadvantage, as the new technology was in general use by the Royal Navy at this time. After the introduction of gunlocks, linstocks were only as a backup means of firing; the linstock slow match or the spark from the flintlock ignited the priming powder, which in turn set off the main charge, which propelled the shot out of the barrel. When the gun discharged, the recoil sent it backwards until it was stopped by the breech rope, a sturdy rope made fast to ring bolts let into the bulwarks, with a turn taken about the gun's cascabel.
A typical broadside of a Royal Navy ship of the late 18th century could be fired 2–3 times in 5 minutes, depending on the training of the crew, a well trained one being essential to the simple yet detailed process of preparing to fire. The British Admiralty did not see fit to provide additional powder to captains to train their crews only allowing 1⁄3 of the powder loaded onto the ship to be fired in the first six months of a typical voyage, barring hostile action. Instead of live fire practice, most captains exercised their crews by "running" the guns in and out, performing all the steps associated with firing but without the actual discharge; some wealthy captains, those who had made money capturing prizes or who came from wealthy families, were known to purchase powder with their own funds to enable their crews to fire real discharges at real targets. A complete and accurate listing of the types of naval guns requires analysis both by nation and by time period; the types used by different nations at the same time were different if they were labelled similarly.
The types used by a given nation would shift over time, as technology and current weapon fashions changed. Some types include: Demi-cannon Culverin Demi-culverin Carronade Paixhans gunOne descriptive characteristic, used was to define guns by their pound rating — theoretically, the weight of a single solid iron shot fired by that bore of cannon. Common sizes were 42-pounders, 36-pounders, 32-pounders, 24-pounders, 18-pounders, 12-pounders, 9-pounders, 8-pounders, 6-pounders, various smaller calibres. French ships used standardized guns of 36-pound, 24-pound, 18-pound, 12-pound, 8-pound calibers, augmented by carronades and smaller pieces. In general, larger ships carrying more guns carried larger ones as well; the muzzle-loading design and weight of the iron placed design constraints on the length and size of naval guns. Muzzle-loading required the cannon to be positioned within the hull of the ship for loading; the hull width, guns lining both sides, hatchways in the centre of the deck limited the room available.
Weight is always a great concern in ship design as it affects speed and buoyancy. The desire for longer guns for greater range and accurac
Rifled breech loader
A rifled breech loader is an artillery piece which, unlike the smoothbore cannon and rifled muzzle loader which preceded it, has rifling in the barrel and is loaded from the breech at the rear of the gun. The spin imparted by the gun's rifling gives projectiles increased range. Loading from the rear of the gun leaves the crew less exposed to enemy fire, allows smaller gun emplacements or turrets, allows a faster rate of fire; the major problem to be solved with breechloading artillery was obturation: the sealing of the breech after firing to ensure that none of the gases generated by the burning of the propellant escaped rearwards through the breech. This was both a safety issue and one of gun performance – all the propellant gas was needed to accelerate the projectile along the barrel; the second problem was speed of operation – how to close the breech before firing and open it after firing as as possible consistent with safety. Two solutions were developed more or less in parallel, the "screw breech" block and "sliding wedge" or "sliding block".
At the time of development of the first modern breechloaders in the mid-19th century, gunpowder propellant charges for artillery were loaded in cloth bags, which combusted on firing. Hence, unlike with a metal rifle cartridge, the breech mechanism itself somehow needed to provide obturation; the early "screw" mechanisms for sealing the breech consisted of threaded blocks which were screwed into the breech after loading, but the threads themselves were insufficient to provide a gas-tight seal. This was further complicated by the need to screw and unscrew the breech as as possible. Hence if the block circumference was divided into two sets of threads and gaps, the block only needed to be rotated ¼ turn to lock it instead of several turns; the tradeoff was that only ½ the block's circumference was threaded, reducing the security accordingly. The other possibility of sealing the breech was to enclose the propellant charge in a metal cartridge case which expanded on firing and hence sealed the breech, leaving the breech-block needing to lock the cartridge case in place.
This was more accomplished by sliding the block in behind the cartridge case through a vertical or horizontal slot cut through the rear of the breech: the "sliding wedge" or "sliding block" breech. The first cannons of the Middle Ages were breech loaded, with gunpowder and shot contained in pots dropped at the back of the barrel, but the poor seals made them dangerous, they wore and could not be scaled to larger weapons; until the 19th century, only muzzle-loaders were used. In 1837 Martin von Wahrendorff patented a design for a breech-loader with a cylindrical breech plug secured by a horizontal wedge. Independently, Giovanni Cavalli first proposed a breech-loader gun in 1832 to the Sardinian Army, first tested such a gun in 1845. Advances in metallurgy in the industrial era allowed for the construction of rifled breech-loading guns that could fire at a much greater muzzle velocity. After the British artillery was shown up in the Crimean War as having changed since the Napoleonic Wars the industrialist William Armstrong was awarded a contract by the government to design a new piece of artillery.
Production started in 1855 at the Royal Arsenal at Woolwich. His "Armstrong screw" breech involved loading the shell and gunpowder propellant charge in a cloth bag through the hollow breech screw, lowering a heavy block into a slot behind the powder chamber and screwing the breech screw against the block to lock it in place. A degree of obturation was achieved via a cup on the face of the block being forced into a recessed ring on the chamber face; the system was in effect a vertical sliding block such as used by Krupp in both horizontal and vertical form, with the crucial difference that Armstrong failed to make the progression to loading the powder charge in a metal cartridge, with the result that complete obturation was impossible. Whatever obturation, achieved relied on manual labour rather than the power of the gun's firing, was hence both uncertain, based on an unsound principle and unsuited to large guns. Armstrong screw-breech guns were adopted by the British Army and Royal Navy, but concerns about limited armour penetration of the shells due to limited maximum velocity, safety concerns with the breech blocks blowing out of guns, higher skill levels demanded of gunners led the British Government to revert to rifled muzzle-loaders from 1865 to 1880, when Britain deployed reliable screw breech mechanisms.
The Imperial Japanese Army used Armstrong cannon during the Boshin War to devastate the Aizu castle town and force its inhabitants to surrender and British Armstrong light field guns proved deadly against Chinese forces in the Second Opium War. However, the British Army and Navy preferred to revert to muzzle-loaders until larger high-powered breech-loaders with secure obturation systems that were simple to operate were developed. In the meantime the French persevered with trying to develop breechloaders which combined faster loading than muzzle-loaders, high power and solved the problem of obturation; the Lahitolle 95 mm cannon of 1875 with an interrupted screw breech met the first three requirements to a great extent and solved the obturation problem. The de Bange system introduced in 1877 solved the obturation problem with an asbestos pad imp
A smoothbore weapon is one that has a barrel without rifling. Smoothbores range from handheld firearms to large artillery mortars; the majority of shotguns are smoothbores and the term can be synonymous. Early firearms had smooth barrels. To minimize inaccuracy-inducing tumbling during flight their projectiles required stable shape, such as a sphere. However, the Magnus effect causes spheres rotating randomly during flight to curve when spinning on any axis not parallel to the direction of travel. Rifling a barrel with spiral grooves or polygonal rifling imparts a stabilizing gyroscopic spin to a projectile that prevents tumbling in flight. Not only does this more than counter Magnus-induced drift, but it allows a longer, heavier round to be fired from the same caliber barrel, increasing both range and power. In the eighteenth century, the standard infantry arm was the smoothbore musket. Artillery weapons were smoothbore until the middle 19th century, smoothbores continued in limited use until the 1890s.
Early rifled artillery pieces were patented by Joseph Whitworth and William Armstrong in the United Kingdom in 1855. In the United States, rifled small arms and artillery were adopted during the American Civil War. However, heavy coast defense Rodman smoothbores persisted in the US until circa 1900 due to the tendency of the Civil War's heavy Parrott rifles to burst and lack of funding for replacement weapons; some smoothbore firearms are still used. A shotgun fires round shot. While this may be acceptable at close ranges this is not desirable at longer ranges, where a tight, consistent pattern is required to improve accuracy. Another smoothbore weapon in use today is the 37-mm riot gun, which fires non-lethal munitions like rubber bullets and teargas at short range at crowds, where a high degree of accuracy is not required; the cannon made the transition from smoothbore firing cannonballs to rifled firing shells in the 19th century. However, to reliably penetrate the thick armor of modern armored vehicles many modern tank guns have moved back to smoothbore.
These fire a long, thin kinetic-energy projectile, too long in relation to its diameter to develop the necessary spin rate through rifling. Instead, kinetic energy rounds are produced as fin-stabililzed darts. Not only does this reduce the time and expense of rifling barrels, it reduces the need for replacement due to barrel wear; the first tank with a smoothbore gun was the Soviet T-62, introduced into service in 1961. Today all main battle tanks field them except the British Challenger 2 and Indian Arjun MBT. While the 73 mm gun of the early Soviet infantry fighting vehicles BMP-1 and BMD-1 was a smoothbore, their more recent successors BMP-3 and BMD-4 use a rifled 100 mm gun; the Russian navy conducted experiments with large-caliber smoothbore naval guns, which were halted by budget cuts. The armour-piercing gun evolution has shown up in small arms the now abandoned U. S. Advanced Combat Rifle program; the ACR "rifles" used smoothbore barrels to fire single or multiple flechettes, rather than bullets, per pull of the trigger, to provide long range, flat trajectory, armor-piercing abilities.
Just like kinetic-energy tank rounds, flechettes are too long and thin to be stabilized by rifling and perform best from a smoothbore barrel. The ACR program was abandoned due to poor terminal ballistics. Mortar barrels are muzzle-loading smoothbores. Since mortars fire bombs that are dropped down the barrel and must not be a tight fit, a smooth barrel is essential; the bombs are fin-stabilized. Rifling Buck and ball Cap gun Caplock mechanism Internal ballistics Tubes and primers for ammunition Minié ball Gunpowder Cannon Muzzleloader Muzzle Gun barrel Projectile
An Anti-tank gun is a form of artillery designed to destroy tanks and other armored fighting vehicles from a static defensive position. The development of specialized anti-tank munitions and anti-tank guns was prompted by the appearance of tanks during World War I. To destroy hostile tanks, artillerymen used field guns depressed to fire directly at their targets. However, this practice expended too much valuable ammunition and was of limited effectiveness as tank armor became thicker; the first dedicated anti-tank artillery began appearing in the 1920s and by World War II was a common appearance in many European armies. In order to penetrate armor they fired specialized ammunition from longer barrels to achieve a higher muzzle velocity than field guns. Most anti-tank guns were developed in the 1930s as improvements in tanks were noted, nearly every major arms manufacturer produced one type or another. Anti-tank guns deployed during World War II were manned by specialist infantrymen rather than artillery crews, issued to light infantry units accordingly.
The anti-tank guns of the 1930s were of small caliber. As World War II progressed, the appearance of heavier tanks rendered these weapons obsolete and anti-tank guns began firing larger and more effective armor-piercing shot; the development of the compact hollow charge projectile permanently altered anti-tank warfare, since this type of ammunition did not depend on a high muzzle velocity and could be fired from low-recoil, man-portable light weapons, such as the Panzerfaust and the American series of recoilless rifles. Although a number of large caliber guns were developed during the war that were capable of knocking out the most armored tanks, they proved expensive and difficult to conceal; the generation of low-recoil anti-tank weapons, which allowed projectiles the size of an artillery shell to be fired from a man's shoulder, was considered a far more viable option for arming infantrymen. Recoilless rifles replaced most conventional anti-tank guns in the postwar period. A few Soviet designs saw combat well into the 1980s.
The People's Republic of China was still producing large caliber anti-tank guns as late as 1988. The first specialized anti-tank weaponry consisted of anti-tank rifles; these emerged from the mixed results of deploying field artillery against tanks during World War I, the need to produce a more economical weapon to destroy them. Most anti-tank rifles were over 1.3m in length and difficult for infantrymen to operate in the confines of their trenches. They could penetrate a tank's armor at long range, but without explosive firepower failed to cause catastrophic damage, kill or seriously injure the crew, or disable the tank. A number of infantry support guns designed to defeat hard targets such as fortified machine gun emplacements were used as makeshift anti-tank weapons, including the French Canon d'Infanterie de 37 modèle 1916 TRP; the 3.7 cm Tankabwehrkanone 1918 im starrer Räder–lafette was the first dedicated anti-tank gun in service. However, its gun barrel was based on an earlier Hotchkiss 5- barrelled rotary-cannon.
The 3.7 cm TAK 1918 was designed and built for the Imperial German Army in 1918. The 3.7 cm Pak 36 which first appeared in 1928 was the first purpose built anti-tank gun. Weighing some 160 kg, the Pak 36 could inflict a catastrophic kill on a tank rather than penetrating its armor plate. Towed guns similar to the Pak 36 were the only anti-tank weapon issued to European armies during the 1930s, a number of influential designs proliferated, such as the Böhler gun. By the late 1930s, anti-tank guns had been manufactured by companies in Germany, France, Belgium, Great Britain and Sweden. A few countries, such as the Soviet Union manufactured foreign designs under license. At the outbreak of World War II, most armies were fielding light anti-tank guns firing 3.7 cm ammunition. The guns were mounted on two-wheeled carriages so they could be towed into position withdrawn and repositioned rapidly. Since they weighed only a few hundred pounds on average, they could be manhandled into position. All fired high-explosive and solid armor-piercing shot effective at medium range, an increasing number were manufactured with protective gun shields in addition to a split rail mounting.
They were able to destroy tanks fielded by both sides during the first two years of the war, but soon proved impotent against the heavier tank armor that debuted in 1940. Introducing improved ammunition and increasing muzzle velocity helped compensate for their mediocre performance, but it was clear that small caliber anti-tank guns would soon be overtaken by yet more armored tanks. Medium caliber guns in the 40mm to 50mm range began to appear, some of which utilised rebored 37mm barrels. Although they too were soon approaching obsolescence, most remained in use with infantry units until the end of the war. Anti-tank guns remained ineffective against sloped armor, as demonstrated by an incident in 1941 when a single Soviet T-34 tank was hit more than 30 times by a battalion-sized contingent of German 37mm and 50mm anti-tank guns; the tank was driven back to its own lines a few hours later. This helped earn the Pak 36 the moniker of Panzeranklopfgerät because its crew revealed their presence and wasted their shells without damaging the T-34's armor.