Maroszek Kb Ur wz.35 (Anti-tank rifle)



In appearance it resembled a rifle with a longer-than-normal barrel supported by a bipod at the front of the wooden stock. It was a bolt-action rifle, fed from a 4-round box magazine. The barrel was equipped with a muzzle brake to limit the recoil. The brake absorbed approximately 65% of the shot energy and the recoil was comparable to the standard Mauser rifle, even though the cartridge carried more than twice the amount of propellant. It had fitted iron sights fixed for a 300-meter range.

Unlike other anti-material rifles of the time, the wz. 35 did not use an armour-piercing bullet with a hard core, but rather a lead core, full metal jacket bullet weighing 14.579 g; due to the high muzzle velocity this was effective even under shallow angles, as instead of ricocheting, the bullet would "stick" to the armour and punch a roughly 20 mm diameter hole.[1] Calculated kinetic energy, by shot, before brake was about 11,850 J. The high energy was due to the relatively long barrel, and nitro powder giving a muzzle velocity of 1,275 m/s.[

The Maroszek Kb Ur wz.35 anti-tank rifle was developed in Poland in mid-1930s, and kept under strict secrecy, which resulted in limited use of this weapon during the German attack on the Poland in 1939, despite the fact that this weapon was effective enough to deal with German tanks of the period. Some Maroszek Kb Ur wz.35 anti-tank rifles were captured by German army, where these were known as PzB 35(p). The peculiar name "Kb Ur" comes from the attempt of the Polish army to disguise this development as the "rifle for Uruguay". Rifle was built around proprietary, rifle-caliber round (metric designation 7.92x107), which had very long and slender case, and was loaded with conventional, lead-cored jacketed bullet (12.8 gram, 1220 m/s). Due to the very high muzzle velocities, the barrel life of the rifle was relatively short (barrels normally had to be replaced every 300 rounds or so). Total production of the wz.35 anti-tank rifles is estimated at about 6 500 guns, which were delivered to Polish army before the German occupation.

The Maroszek Kb Ur wz.35 anti-tank rifle is amanually operated, bolt action rifle. It uses Mauser-type rotary bolt with frontal locking lugs. Feed is from detachable box magazine which holds 4 rounds. Rifle is equipped with traditional wooden stock and folding bipod. The long barrel is fitted with effective muzzle brake. Iron sights are of fixed type, set for 300 meters range.
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, beginning in July 1939, and had to swear to 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 aide 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 period (the Panzer I, II and III, as well as the Czech-made LT-35 and LT-38) at 100 meters. At up to 400 meters it could penetrate all lightly armored vehicles. It could penetrate 15 mm of armor, sloped at 30° at 300 m distance, or 33 mm of armor at 100 m. Interestingly, an Italian manual stated maximum penetration as 40 mm.

Panzerbüchse 35(p)
Despite well-established opinion, the Karabin przeciwpancerny wz.35 was extensively used during the Invasion of Poland 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 Panzerbüchse 35 (polnisch) (PzB 35(p)), and sped up work on their own simplified, one-shot anti-tank rifle Panzerbüchse 39 (PzB 39). According to some sources, however, the Germans replaced the DS bullets in the captured ammunition with their own 7.92 mm hardened-steel-core bullets from the PzB 39.

Also, several features of the Polish rifle, most notably the lock, were used in developing the Soviet PTRD, 14.5 mm anti-tank rifle.

In 1940, Germany sold some 800 Polish antitank rifles to the Italian armed forces, which used them in combat under the designation Fucile Controcarro 35(P) until the end of World War II.