Wz 35 Anti - Tank rifle The Wz . 35 was a rifle designed around an extremely powerful tungsten ammunition , which was later copied by the Germans . Had a superior design to the contemporary genre , such as a brake mouth extremely efficient , which reduced 65 % of the recoil of the gun . Although the concept of anti - tank rifle be approaching obsolescence , this weapon was capable of penetrating all tanks used in the invasion of Poland in 1939 . Taking advantage of these qualities , of the approximately 6 , 500 produced was incorporated into the German army and used in the Russian campaign , as the PZB 35 ( p ) . Techinical Description . Ammunition . In late 1920s the Polish General Staff started the development of a light anti - tank weapon for the Polish infantry . In 1931 Lt . colonel Tadeusz Felsztyn from the Institute of Armament Technology in Warsaw started the first tests of various low - calibre cartridges . After the tests of a German - made Hagler bullets proved the possibilities of such ammunition in perforation of steel plates , the National Ammunition Factory in Skarżysko - Kamienna was ordered to develop its own 7 , 92 mm bullet with the muzzle velocity of over 1000 metres per second . After a series of tests , a new " DS " bullet was proposed . The " DS " ammunition was based on a standard 7 , 92 mm bullet used by both the Mauser rifles Model 1898 ( wz . 98 ) and its Polish variant karabinek wz . 29 . The length of the cartridge was extended to 131 , 2 mm and the overall weigth reached 64 , 25 g . After an additional series of tests the initial copper cartridge case was replaced with a case made of brass ( an alloy of 67 % of copper and 23 % of zinc ) . A unique feature of the kb ppanc wz . 35 was , that instead of using penetrating cores made of tungsten or other hard metals , DS bullet had leaden core in a steel coating , just like ordinary rifle bullets . Its core was not penetrating the armour , but it was flattening on an armour plate , transferring its kinetical energy . The key to success was very high bullet velocity . As a result , the bullet was punching a cork in an armour , about 20mm of diameter , which was more , than rifle caliber . Rifle . Simultaneously to the development of the ammunition , a young graduate of the Warsaw University of Technology Józef Maroszek was ordered to prepare an anti - tank rifle . On August 1 , 1935 , the " Committee of Equipment and Armament " officially ordered the rifle and in October the first tests of the new weapon started . The rifle was based on the successful construction of the Mauser rifle , a standard pre - WWI infantry weapon . The gun - lock was modified to sustain higher pressure of the new bullet and the muzzle was extended significantly . The first tests carried out in Brześć and Pionki showed that the new weapon was capable of perforating a 15mm steel plate from the distance of 300 metres . Similar results were reached after firing at a deflected steel plate . Initially the new muzzle could only sustain up to 30 shots , after which it had to be replaced with a new one . However , this drawback was soon corrected and the final prototype could fire approximately 300 shots . The committee accepted the new design on November 25 , 1935 , and in December the Ministry of Military Affairs ordered the delivery of 5 rifles , 5000 bullets and a set of spare muzzles for further tests . After the tests carried out by the " Centre of Infantry Training " in Rembertów proved high effectivity and reliability of " kbk ppanc wz . 35 " , the Ministry ordered 7610 rifles to be delivered to the Polish Army by the end of 1939 . It is uncertain how many rifles were actually produced , but it is often estimated that there were more than 6500 pieces delivered by September 1939 . Usage . The rifle was the main anti - tank weapon of an infantry platoon . Each infantry company and cavalry squadron was to be equipped with three rifles , each operated by a team of two soldiers . Additional anti - tank teams were to be created at a later stage . Although the weapon was successively introduced to the units , it remained a top secret . The rifles were kept in closed wooden crates , each marked with a number and a notice " do not open ; surveillance equipment " . The teams were trained in secret military facilities just before the war , starting from July 1939 , and then had to give an oath that they will preserve the secret . The rifle was carried by the leader of the two - man rifle team on a carrying strap . The other member of the squad was his aid and provided him with cover while he was reloading . The weapon was usually fired from prone supported position with the bipod attached to the barrel . However , it could be also used in other positions , like prone unsupported and crouch . The effective range was 300 metres and the weapon was effective against all German tanks of the epoch ( those being Panzer I , II and III , as well as Czech - made LT - 35 and LT - 38 ) at 100 metres . At up to 400 metres it could destroy all lightly - armoured vehicles . It could penetrate 15mm of armour , sloped at 30° at 300m distance , or 33mm of armour at 100m . What is interesting , an Italian manual stated maximum penetration as 40mm . Despite well - established opinion , the " Karabin przeciwpancerny wz . 35 " was extensively used during the Polish Defence War of 1939 by most Polish units . After Poland was overrun by Germany and the Soviet Union , large quantities of this weapon were captured . The Germans pressed it into service as " Panzer Buchse 35 ( polnisch ) " ( PzB 35 ( p ) ) , and sped up works upon their own simplified , one - shot anti - tank rifle " Panzer Buchse 39 " ( PzB 39 ) . According to some sources , the Germans however replaced DS bullets in a captured ammunition with their own 7 , 92mm bullets with a hardened steel core from the PzB 39 . Also , several features of the Polish rifle , most notably a lock , were used in development of the Soviet Simonov 14 . 5 mm anti - tank rifle . In 1940 Germany sold approximately 800 Polish rifles to the armed forces of Italy , who used it in combat until the end of World War II .