Maroszek WZ 35, polish secret weapon

World War II Other Military Units
#1

Maroszek WZ 35, the polish secret weapon.

The Polish Maroszek WZ 35 was one of the first designs of the 30s.
Clearly inspired in the Mauser tankgewehr it had been conceived and developed by Lt.Col. T. Felsztyn and the engineer Jósef Maroszek in the early 1930ies. First trials in late 1935 proved unsuccessful, because the extremely stressed barrel endured only about 20 shots. After intensive research and testing an almost perfect relation between ammunition characteristics and barrel construction was reached.

The new weapon had a life expectancy of 300 shots. It was integrated into the army in November 1935, simulated battles showed a more than satisfying performance as an anti-tank rifle.

However, the rifle was considered so important that a strict veil of secrecy was put over the whole project, and the delivery crates - containig one Maroszek WZ 35, three replacement barrels and three full ammo magazines - were sealed with the strict order that the seal was only to be broken under direct orders of the defense minister. Until July 1938 only a very restricted and select group of people (again under strict nondisclosure - orders) - mostly military commanders of different command levels - was shown the weapon.

The result was that in many cases the soldiers that were to use it didn’t even see the weapon before WW II started with the german invasion of Poland! Due to all this, this reasonably performing weapon saw only very limited use in the Polish war against the attacking germans; many Polish soldiers ended the short German invasion of Poland still ignorant of the weapon!

The Germans captured considerable numbers of these weapons still unissued in the armories and storages; it received the German designation Panzerbüchse 35(p) (“Tank Rifle”, the suffix “p” for “polnisch”) - abbreviated as PzB 35(p) - but was also called Panzerbüchse 770(p) and was issued to german troops. Some of the weapons were also given to and employed by italian troops.

At least 630 of these polish tank rifles were incorporated into the Wehrmacht and used in the war against the French in 1940. Also a small numeber went to Italy and slovakia, the italians named it “Fucile anticarro Modello 35”.

Muzzle brake.

…

#2

Part II:

The PzB 35(p) was a manual bolt action weapon with a magazine for three rounds. It can easily be recognized by the lack of a pistol grip which is rather uncommon for tank rifles.

The barrel had 6 grooves / right spin and was very long and thin. After 300 shots it had to be changed, which could be accomplished rather quick and uncomplicated with a special key. The well-designed muzzle brake absorbed 65% of the recoil forces and the recoil of the weapon was contrary to other tank rifles only slightly stronger than that of a regular infantry rifle.

The large cartrigde (from Tony Williams site)

The high velocity of the bullet made for an extremely staright flight path, therefore sights at a range of 300m were used. The weapon comes complete with a bipod but can be used without it.
There is a little of debate about what type of bullet it use, some sources say a copper plated lead, but this is completely wrong in my opinion. The heavy barrel wear indicated a hard-core bullet, probably an alloy os steel with high level of chrome and Tugsten. A thing is confirmed, there was no any incendiary or explosive content.

Characteristics.

Muzzle speed. 1,280m/s; length 176cm; barrel length 120cm; weight w/o ammo 9.5kg (10kg with bipod). practical rate of fire: 6-10 rounds per minute.

Penetration in steel plate: Figure vary upon source but about 20-22 mm at 100 meters in a vertical plate ( 90 degrees ) .This plate is equivalent to the side armor of the Panzer IV ausf b & C, both present in the Polish Campaing 1939. :rolleyes:

Please if you found any more pictures of this post it.

#3

More pics at:
http://www.iirp.prv.pl/piechota/karabiny/ur/Dep_piech_karabiny_KbUr.htm

Our Polish friends might help with some translation.

#4

Part ONE (I’m at work and that’s all I can translate now - I’ll try to do some later today - Kovalski)

INTRODUCTION

Famous polish anti-tank rifle was placed in branch of weapons widely spread across the Europe.
Germans were equipped with PzB-39. English had at their disposal Boys M.37 13,97 mm from the mid-30’s.
The Swiss army was equipped with 20 mm rifle. Similiar rifles were in Japan, Finland, Chechoslovakia and USSR.

THE IDEA

First, but timid work on weapon capable to destroy armourde vehicles was carried out in 20’s,
however it was concentrated on artillery, not on low-caliber anti-tank weapon.
Anti-tank rifle was a cheap mean of defence, and that determined such constructions in few countries.

The idea of anti-tank rifle[1] was born during World War 1, when the TuF mk.1919[2] was constructed in Germany.
It was a larger version of Mauser mk. 98, operated by two soldiers. Although it penetrated the 20 mm armor from a distance of 100 m,
it’s low rate of fire, and huge recoil causing a brake of collarbone very often (same injury was caused by the british “Boys” during WW2),
determined the abandonment of that idea of weapon.
However the work at construction of this kind of weapon was not stopped in Germany, what influenced the polish research.
In 1928 Mr Gerlich invented a ultra-fast bullet - Hagler 280 HV Magnum (“beginning speed” of over 1000 m/s).
His research was described in 1931 in “Heerestechnik” magazine (no 4).
Col. dr Tadeusz Felsztyn familiarized with it. He was the one who started the tests with the Hagler ammo in 1931.

I wasn’t able to find the document describing the effect of these tests, but we can assume that it was a part of large-scale research,
because another tests were performed in 1932 with the rifle constructed by Cpt. Kapkowski - it was highly confidental.

THE BULLET RESEARCH

The tests with Hagler ammo gave the data for research on “high beggining speed” bullet.
It was conducted by the Research Office of National Ammunition Factory i Skarzysko-Kamienna.
It’s aim was to construct the 7,92 mm bullet with the “beginning speed” higher than Hagler ammo.
At the beginning the bullet of “SC” type were used - rifle ammo with larger load of gunpowder.
Tests were run with different types of nitro-cellulose gunpowder.
Standard Mauser barrels were used.
After the test with “progressive” gunpowder and new “DS” bullet, the speed of 1300 m/s was reached.
The bullet had the lead core and steel cover ( weight - 14,579 g).
(I’m sorry but I can’t translate all technical vocabulary - Kovalski)
Then, Mr Jozef Maroszek (graduate from Mechanical Department of Warsaw Technical University) entered the research.
At the end of 1931 he was employed in Rifle Factory and constructed the KP-32 rifle.
He started his work on the anti-tank rifle right after the graduation.
Because his team faced some serious problems with the bullet (I’m sorry but I can’t translate all technical vocabulary - Kovalski),
new type of bullet was ready after 2 years. It has a brand new type of shell ( length - 107,67 mm - made of copper in 67 % and zinc in 23 %).
The 11,15 g of non-smoke powder was used. Total weight of a bullet was 64,25 g, and total length of 131, 2 mm.

#5

RIFLE RESEARCH

After successful work on bullet, the new rifle had to be designed. On 1st of August 1935 The Armnament and Equipment Committee made decision about starting the research concerning the anti-tank rifle. This document can be considered as a element of counter-intelligence effort of II Department, in order to mislead the enemy intelligence, because the prototype was present on test site in October 1935 (just a month after documented beginning of research).
The rifle research team:

  • P.Wilniewczyc
  • E. Szetke
  • T. Felsztyn
  • J. Maroszek
    We can assume that the construction lasted from 1933 to 1935.
    The prototype was made by The Armoury no 2 in Warsaw.
    It gone through the endurance tests which shown that the barrel can endure not 30 (as it was in the beginning), but 300 shots.
    Then the tests were ran on Brzesc and Pionki military test grounds.
    During first test shooting the 15 mm steel plate was penetrated from 300 m at angle of 90o. During second test (National Gunpowder Factory in Pionki) the rifle penetrated the 15 mm steel plate, but at angle of 30o (it was quite impressive, because shots fired from that angle were ineffective for that kind of weapon). The holes had the diameters form 14 to 20 mm (3 times larger than weapon’s caliber).
    Mr Maroszek was a part of research team and he is considered as a main constructor. In mechanical system, he used the design taken from his earlier project - KP-32. Meanwhile, another prototype was tested - designed by A. Karczewski, but it couldn’t compete with Maroszek’s rifle.
    It was heavier - 16 kg, when maroszek’s rifle (wz.35) had 9,1 kg.
#6

PRODUCTION OF A WEAPON
On 25th of November 1935 KSUS accepted anti-tank rifle wz. 1935. But it was far from introduction into the army units. In December 1935 The Ministry of Military Affairs ordered Armoury no 2, 5 rifles with 1000 round for each. The rifles were tested in Infantry Training Center in Rembertów. It was assumed that first 1000 rifles will be introduced into the army till May 1937. Due to some technical or financial problems (the author is not sure), they were not delivered. The production of first part of rifles were ordered in PFK in Warsaw. The production proccess was splitted and final assembly took place in secret location at Warsaw Citadel. The first order was put for 7610 rifles, and first 2000 were delivered to the army units in October 1938. Recovered documents confirm the delivery of 3500 rifles till August 1939, but some archives are ambiguous. The analyse of production numbers shows that in fact there were produced 6500 rifles and 15000 barrels. That’s quite large discrepancy between facts and documents. But it seems that number of 3500 rifles is very possible, if we check the numbers of rifles in infantry and cavalry units.
The production cost was 900 PLN (polish zloty). The cost of wz.29 anti-tank rifle was 164 PLN. The cost of “DS” bullet wz. 35 - 0,96 PLN.

THE NAME OF A WEAPON

The official name of a weapon was “karabin przeciwpancerny wz.1935” (anti-tank rifle wz. 1935).
It was rarely used. In order to keep the construction in secret, it was named “Kb UR”, and wz.35 “Ur”.
It could suggest the weapon was designated for export to Urugway.
Other names are: “Kb Export” (technial documents), or “Maroszek’s rifle”. That last name was used for prototypes.
Production name was “kb UR wz.35”.

#7

Fantastic page Dani, many thanks for translating it Kovalski ¡¡, you sure are not a duck :smiley: .

It seems that the polish tested a solid steel bullet but the barrel wear was unbearable. More comments about later no time now.

#8

Another website for the W35, but in English :-

http://hem.passagen.se/dadkri/Wz35.htm

Marek

#9

Thanks 1PUK, it seems that this wean had more use than we believe earlier.

The holes had the diameters form 14 to 20 mm (3 times larger than weapon’s caliber).

That is a big fragmentation effect, ther would be interesting to know about the internal effects.

It has a brand new type of shell ( length - 107,67 mm - made of copper in 67 % and zinc in 23 %).

This alloy have a name, is brass, so if this was the actual bullet they contain no steel core. Problaby the large hole are caused because the proyectile being of a relatively soft material is deformed in the impact. The hiper velocity mades this go through the armor despite this.

Today this kind of solid bullet is still in use, some for large distance shooting and other for hunt thick skinned animals like elephant, crocodrile and Rhinoceros.

Solid brass bullet cal 12,7mm (.50)

I love this pic, the antitank chevalry.

#10

I’ll try to translate the rest later :wink:

#11

By “shell” he meant the cartridge case, which measures 107-108mm in length. The bullet was much shorter.

Tony Williams: Military gun and ammunition website and discussion forum

#12

In this site said that the bullet had no steel in it, not sure how good is that info.

http://www.geocities.com/Augusta/8172/panzerfaust6.htm

#13

I know that there is some debate about this. I have no doubt that some of the ammo would have been “ball” rounds, without an AP core, for training and practice purposes. This was normal (AP ammo was more expensive, and harder on the barrel). I am not certain what was intended to be the AP ammo. I believe that the Germans reloaded the cases with their own Hartkern bullets later.

Tony Williams: Military gun and ammunition website and discussion forum

#14

That was the real secret of the polish gun. It used a normal ball bullet.
The polish find out that core ammunition bring no better performance.
The barrel wear is a problem of the high speed . Even today cartridges over 1000 m/sec
like the .220 swift or. 17 Remington are real barrel killers

#15

I am very dubious about that. Certainly no-one else use lead-cored bullets in preference to hardened steel penetrators in AP ammunition, and tungsten-alloy-cored bullets penetrated about 50% more than steel-cored.

The barrel wear is a problem of the high speed . Even today cartridges over 1000 m/sec like the .220 swift or. 17 Remington are real barrel killers

Yes, high velocity causes increased barrel wear, but so does firing harder bullets. The AP bullets with a hardened steel or tungsten alloy core usually only had a very thin coating of softer metal to take the rifling, so they wore out the rifling faster. Practice ammunition used ordinary ball rounds, or mild (soft) steel.

#16

I am very dubious about that. Certainly no-one else use lead-cored bullets in preference to hardened steel penetrators in AP ammunition, and tungsten-alloy-cored bullets penetrated about 50% more than steel-cored.

My opinion is that it used “solid” brass bullet, no lead core.

Remember that:

The holes had the diameters form 14 to 20 mm (3 times larger than weapon’s caliber

You only can achieve that if the bullet diformated in impact…a steel core would diformate in that way ?

dont think so.

#17

On checking, the only Polish production bullet known had a lead core. The Germans later loaded the cases with their usual tungsten-alloy cored bullets.

#18

I have no definative answer on the question of what type bullet the round used, but it was common practice to use solid bronze bullets for A.P. applications. (and is to this day) While deformation is present, the material retained enough ballistic integrity to complete the job. Brass, and bronze look much alike, so maybe that was the stuff.

#19

Oh…just let we say that wasnt a steel bullet.

#20

:confused: The only solid bronze or brass military bullets I know of were in the original 8mm Lebel, and in some modern long-range sniping rounds. In the latter case, the material is chosen because it is homogenous and its quality can be more easily controlled than for a multi-part bullet. Armour piercing has nothing to do with it.

AP projectiles come in three flavours, in increasing order of merit: those with a hardened steel core, those with a tungsten alloy core, and those with a depeleted uranium core.