Anti-Ferdinand Guide

I have previously written about brochures describing how to take out German tanks, and posted excerpts from them. I have since found a full version of one of them, the one describing how to take out a Ferdinand. You can find it here.

"Weak points of the German Ferdinand SPG and methods of combat with it" is a mouthful of a title, but very descriptive. The upper right corner helpfully reminds you: "Death to the German occupants!". The lower part of the page holds the publisher information: military publishers of the People's Commissariat of Defense, Moscow, 1943. 

The booklet doesn't waste time on introductions, and gets straight to the point.

"Weak points and methods of combat with the Ferdinand SPG

1. Suspension

The suspension puts the SPG in motion. The most vulnerable parts of the suspension are the rear most-wheel (idler), front-most wheel (drive wheel), and road wheels. 

Artilleryman! Open fire at the suspension with AP and HE shells of all calibers from all distances. The SPG will stop.

Blow up the bottom of the hull and suspension with mines.

Sapper-miner! Quickly set up mines on likely directions that the SPG will move in. Keep an eye on the SPG's movements. Prepare surprises for the Ferdinand.

2. Lower vertical plate

Components of the SPG are located past the lower vertical plate. 

Open fire with: APCR from 45 mm guns at 500 meters.

AP or APCR from larger caliber guns at 500-1000 meters.

3. Turret armour plates

The crew is present in the turret, as well as the gun mechanisms and ammunition.
Open fire: from a 57 mm gun with AP shells at 1000 meters.
From 76 mm model 02/30, 39, and 42, with APCR shells at 300-500 meters.
From 76 mm and 85 mm AA guns: with AP from 300 and 1000 meters.

4. Upper vertical hull plate and rear armour

The ammunition is stored behind the vertical part of the rear armour, and gas tanks and engine are located behind the front part. The lower sloped plate covers the electric motors. The exhaust system is behind a hatch in the center. The upper sloped plate has an emergency hatch.
Open fire from a 57 mm gun at 1000 meters.
From 76 mm model 02/30, 39, and 42, with APCR shells at 300-500 meters.
From 76 mm and 85 mm AA guns: with AP from 300 and 1000 meters.

5. Driver, radio man, and engine hatches

One of the weak parts of the SPG is the hatch on top of the gas tank.
Open fire at the lower part of the upper front plate with HE shells of all calibers.
Hit the hatches with AT grenades. Hit the air intakes with incendiary fluid.

6. Bottom of the hull

When the SPG climbs a hill, it exposes the bottom of the hull.
Open fire with any caliber gun at any distance.

Brief data on the Ferdinand SPG

Size
Length: 7 m
Width: 3.5 m
Height: 3 m
Mass: about 70 t

Armour thickness:
Front (lower, sloped): 85 mm
All other front: 200 mm
Side, vertical: 85 mm
Turret side: 85 mm
Lower vertical plate: 50 mm
Roof, including driver and radio operator hatches: 45 mm
Roof above the engine and air intake hatch: 45 mm

Observation devices and ports:
There is a periscopic observation device above the driver. There is a removable panoramic sight for the gun on the roof of the turret. There are openings for personal weapons.

Hatches:
The front part of the SPG has hatches for the driver, radio operator, two engine compartment hatches, and two gas tank hatches. The roof has 3 hatches, and 2 small hatches in the corners. The rear plate has a large hatch, and a small hatch in it.

Engines:
Two Maybach gasoline engines, with 300 hp each, are located behind the driver. The engines are equipped with generators.

Gas tanks and radiators:
550 liter gas tanks are located next to the engines. The radiators are located next to the generators.

Suspension:
The rear wheel is the drive wheel, there are 6 road wheels per side.

Armament:
Gun: 88 mm
Ammunition: 70-90 rounds
Machine gun: MG-42
Ammunition: 2000 bullets"

The next three pages are diagrams that I have already translated in the linked article. After that is a pretty self explanatory part (shoot at the gun and observation devices to make the SPG useless), a table of everything we learned in the previous part, and some credits.

The very last page has a picture of how one would place AT mines on a Ferdinand's path ("use mobile AT mines") and some words of encouragement: "Artilleryman, tanker, tank hunter! Bravely let the Germano-fascist Ferdinand SPG approach, coolly aim, and surely strike at weak points! Tanker Lieutenant A. Erohin destroyed 6 Ferdinand SPGs. Comrade Erohin, with brave and decisive ambush maneuvers, destroyed Ferdinands in battle by opening fire from 500-1000 meters at their engines and gas tanks."

Thanks to the magic of the Internet, Erohin's memoirs are readily available. This is what he writes on his encounter with Ferdinands:

"It wasn't a tank, it was like a giant box. It was powerful, I could tell by the way the shells flew... Their battalion started taking up positions to support infantry. Behind the column of smoke, several more of these vehicles approached. One tried to get up a hill, and the entire company opened fire at its side. It stopped. The rest turned around and opened fire at us. After obtaining my commander's permission, I went in from the flank, behind hills and bushes. Peeking out from behind a hill, I fired five times at  the closest tank. It started smoking. The rest started backing off. Their turrets could not turn, and my flanking maneuver put them in a bad position. If they turned to fire at me, they would become vulnerable to our other tanks, and currently, they were vulnerable to me. Soon, it became dark, and the German attack failed."

Considering that his tank was a plain T-34-76, Erohin did pretty well. Here are some excerpts from his award orders:

"Over three days [Note: July 5-7, 1943] Lieutenant Erohin and his courageous crew destroyed 3 Tiger tanks and 10 Germans"

"On November 2nd, 1943, comrade Erohin met an ambush of enemy SPGs. In an uneven battle, he went for a flanking maneuver, and destroyed four SPGs from the rear."

"On November 5th, 1943, in battles for the village Sinyak, the enemy offered heavy resistance, delaying our advance. Comrade Erohin, on his tank, bravely penetrated the enemy defenses, destroying enemy soldiers and equipment. During the battle, he destroyed 128 soldiers and officers, two light tanks, one gun, and four machine guns. For courage and heroism in the fight with German invaders, for the destruction of enemy soldiers and equipment, comrade Erohin is worthy of the title of Hero of the Soviet Union."

World of Tanks History Section: Ferdinand

On April 20th, 1942, Hitler was shown experimental heavy tanks developed by Henschel and Porsche. They impressed the fuhrer, and he gave the order to mass produce both. However, a series of reasons forced the choice of Henschel's model exclusively. At the same time, the need for a self propelled mount for the Rheinmetall 88 mm PaK 43 arose. The project required 200 mm of front armour, and limited the mass at 65 tons. Unused Porsche chassis served as a basis for the SPG.

Work started in September of 1942. The project was developed by Porsche and Alkett. Due to the long gun, Porsche selected a rear casemate placement, and engine placed in the middle. There is an opinion that the chassis was reversed. That opinion is false: both the tank and the SPG "looked" in the same direction. This can be seen by looking at the drive wheel: in both vehicles, it is in the rear.

In February of 1943, Hitler personally named this vehicle "Ferdinand", in honour of its creator. On February 16th, 1943, Nibelungenwerke started producing Porsche's creation.

The casemate of the SPG consisted of a truncated four-faced pyramid. It was made with cemented naval armour. The front armour of the hull, initially 100 mm thick, was reinforced with another plate, which was held on with rivets. The side and rear armour was thinner: only 80 mm. The rear of the casemate had a round hatch for removing the gun, loading ammunition, and emergency crew evacuation.

The gun opening was covered with a pear-shaped mantlet. It was quickly discovered that this was a poor solution, since when the mantlet was hit, small shards and molten metal droplets entered the vehicle. To mitigate this, nearly all Ferdinands got a square armour plate welded to their mantlet.

Because the fighting compartment was in the rear, and engine in the middle, the crew was separated. The casemate had the commander, gunner, and two loaders. The front had the driver and radio operator. The compartments were separated with metal walls, which made using an internal communication system necessary.

The thick armour and powerful gun made the Ferdinand a dangerous enemy. Its shells could penetrate Soviet tanks from 1000 meters, while Soviet tanks had to get much closer, or the German armoured monster would be invincible.

However, nothing is ideal. Porsche's creation was too heavy, had poor off-road performance and mobility. Before every mission the route had to be thoroughly scouted.

If you examine memoirs, you will find that Ferdinands were produced by the thousand, and fought on every section of the front. In reality, only 90 were built, and the only massed use of them was at the northern part of Kursk, next to the Ponyri railroad station and Teploye village, between two divisions.

The Ferdinands met their trial by fire there, and it was not an easy one. Armour played its part, and most losses were due to mine fields. Only one vehicle was met with concentrated fire from seven Soviet tanks and a 76 mm gun battery, and was found with a breach next to its drive wheel. Three more Ferdinands were destroyed by hits from an incendiary bottle, large caliber howitzer shell, and a direct hit from a bomb, respectively.

The only Soviet vehicle capable of fighting the Ferdinand one-on-one was the SU-152. They knocked out four Ferdinands in one battle.

After Kursk, Ferdinands were recalled to France and Austria for repairs and modernization. One of the most important changes was a machine gun in a ball mount in the front of the hull. Previously, the vehicle had no defense against infantry, and this could prove fatal in real combat conditions. A commander's cupola was added, and the mantlet shield was flipped, welding seams out. This made it easier to attach. The ammunition capacity increased to 55 shells. The SPG was renamed to "Elefant", but it was more frequently called by its original name, "Ferdinand".

Despite relatively few Ferdinands fighting in the Eastern Front, they became a bit of a legend. Any German SPG could be called a Ferdinand, even if it looked nothing alike. Also, anyone that destroyed a Ferdinand would receive an order, which caused many to assign themselves such a notorious victory.

An attempt to use Ferdinands in 1944 in Italy was a failure. 11 vehicles were sent there, but it turned out that local ground is not suited for them. The SPGs sank under fire, and the Germans had no chance to evacuate them due to constant artillery fire. Several vehicles were knocked out by American aircraft. On August 6th, only 3 Ferdinands returned to Austria.

On May 1st, 1945, two last Ferdinands were captured by Soviet and Polish soldiers during battles near the Karl-August square.

Original article available here.

The Last TK

These are photographs of a Polish TK-3 tankette. Fans of this particular type of vehicle might recognize it as serial number 194, with the proper name "szwadron śmierci" ("Death Squadron"). It was built on July 20th, 1936. Initially, it was used by the 10th Armoured Cavalry Brigade (10 Brygada Kawalerii Pancernej), but then it was captured by Soviet forces, along with 18 other Polish tanks and tankettes, and 2 German tanks. Two TK-S tankettes were sent to Kiev, where #194 was restored for testing, and eventually ended up in Hangar #7 (captured vehicles) at the Kubinka Tank Museum. 

CAMD RF 38-11355-12

"Technical Inspection Act

On January 14th, 1941, a commission consisting of chairman Military Engineer 2nd Grade comrade N.S. Salmin, and members Intendant-Technician 1st Grade comrade I.I. Stepanov, and Junior Military Technician comrade V.P. Gornih, as a result of orders from the assistant chief of the proving grounds, Military Engineer 1st Grade, comrade Gluhov, inspected a TK-3 (Polish tankette, #1621/109) for the purpose of recycling it as special metal and removing it from the proving grounds inventory. 

After familiarizing themselves with the proper documents and inspecting the vehicle, it was discovered that:

1. The TK-3 Polish (captured) tankette that arrived at the proving grounds from repair base #7 was disassembled for parts in order to repair two TK-3 tankettes, #194/1725 and #128. The following parts were removed:
1. Engine
2. Side friction clutches
3. Two fan covers
4. Water cooling radiator
5. One fan
6. Driver's hatch
7. Towing equipment
2. The commission concludes that the hull of the tankette may be sent to the factory as coloured metal and removed from the inventory of the GABTU KA proving grounds."

#194 remains the only TK tankette with all original parts.

German Paint

We've seen trials of German tanks, trials of German guns, now it's time for something a little different. A trial of German...paint!

CAMD RF 38-11355-4

"To the chief of the Directorate of Armoured and Tank Forces of the Red Army, Military Engineer 1st class, comrade Korobkov.

As a part of a series of foreign purchases by the Red Army UVHZ, we received three types of oil and fat resistant "R-series" paints for armoured cars from the Herbig-Haarhaus factory:

• Red-brown R-1 for primer
• Khaki
• Ivory R-13 for surfaces

Of these paints, we can allot the following amounts to BTU KA:

• R-1: 2550 kg
• Khaki: 1260 kg
• R-13: 1258 kg

Attached are the Conditions of Delivery and instructions for using these paints. Please reply with your confirmation and indicate which warehouse to send the paints to.

Attachment: 3 pages of German text.

Deputy Chief of the Red Army NIHI, brigade engineer Korolev

Chief of the information division, military engineer 3rd class, Kondratyev

November 27th, 1940"

BR-23 450 mm Howitzer

CAMD RF 81-12104-38

"To the Deputy People's Commissar of Defense and Head of GAU KA Marshall of the Soviet Union, comrade Kulik.

In 1940, factory #221, based on AU's tactical-technical requirements, developed a project of a 450 mm howitzer, which was approved by ZhAK #0012-40g. 

In the same year, the factory developed a technical project, which was examined and approved for the production of working blueprints.

The journal for examination of this technical project is composed, but still not approved by you.

The factory, not waiting for approval, began, and has almost finished, the creation of working blueprints. 

The UVNA GAU plans for 1941 include an experimental 450 mm howitzer, but due to the unconfirmed nature of the situation, the contract has not been signed and production has not started. 

I am reporting this, and waiting for further instructions on whether or not to sign a contract in the current year for the production of a 450 mm howitzer prototype and ammunition for it.

Chief of the UVNA GAU KA

Military engineer 1st grade, Lipin."

The document is dated February 1st, 1941. There was not enough time before the start of the war to develop such a massive device, but a model was built.

And here's some more technical data:

The artillery unit is transported on 7 25 ton railroad carts (the total mass of the system was "only" 110 tons). The rate of fire was 1 shot every 5 minutes. The gun fired two shells: one concrete penetrating (projected to penetrate 3 meters of reinforced concrete at 9.5 km), which weighed 1500 kg and contained 150 kg of explosives, and an HE grenade (projected to create a crater 230 cubic meters in size), which weighed 1060 kg and contained 159 kg of explosives.

World of Tanks: Today in History: Happy Birthday, T-34

Experience in the Spanish Civil War demonstrated that the era of tanks with bulletproof armour has come to an end. These tanks were a perfect target for light and fast-firing anti-tank guns. Engineers were tasked with making a tank with shell-proof armour.

In 1937-1938, Kharkov factory #183 worked on the A-20 covertible drive tank project, armed with a 45 mm cannon. At the same time, the engineers worked on another project on their own initiative: a tracked vehicle with thicker armour, indexed A-32. It was to be equipped with a 76 mm gun and a V-2 diesel engine.

The engineers managed to prove to the army that the A-32 has promise, despite the latter's preference for the convertible drive. The tracked vehicle had better off-road performance, the diesel engine was more fuel efficient and, at least in theory, more reliable than the gasoline engine. The armament was also better than on the A-20. After government trials in 1939, the tank was renamed T-32, its armour was strengthened, and it was equipped with a 76 mm L-10 gun.

In September of 1939, the T-32, among others, was presented to a government commission which included K. Voroshilov, A. Mikoyan, and A. Zhdanov, among others. The vehicle was driven by N. Nosik. The tank performed well. On December 19th, 1939, the Committee of Defense in the Council of People's Commissars announced decree #443, which accepted the T-34 (the new official name of the tank) into service with the RKKA.

Aside from acceptance into service, decree #443 listed changes to the design. The army wanted better visibility, 45 mm armour, and replacement of the L-10 with a cheaper and better designed F-32. Two prototypes of the T-34 were to be built by January 15th, 1940.

A great and difficult journey awaited the T-34. The vehicle was contraversial and far from ideal, as was any tank in WWII. For us, it will always be a tank of victory, a symbol and legend of the RKKA armoured force.

Original article available here.

From Tank to Infantry

"Mechanic-driver of the 2nd tank battalion of the 10th tank brigade, Junior Sergeant Alexey Savvich Bulba

1. Year of birth: 1921
2. Nationality: Ukrainian
3. Social position: Student
4. Party affiliation: VLKSM member
5. In RKKA since: 1940
6. Participated in the civil war: fighting German fascism
7. Wounds and concussions: none
8. Prior award recommendations, if any: none
9. Prior awards and commendations, if any: none.

Brief summary of personal heroic deed in combat:

From the very start of the Great Patriotic War, BT tank driver comrade Bulba showed courage, as a true son of the great Russian people. He drove into battle in his menacing vehicle many times.

Comrade Bulba performed his heroic deed in battle for the Volobuyevka settlement. The Germans considered Volobuyevka an impenetrable fortress. 

Driver Bulba drove his tank along with his unit. As he approached the outskirts of the village, he saw that one of the houses was a reinforced hardpoint. He alerted the tank commander, and decided to ram through the side of the building. After a strong impact, the vehicle penetrated turret-deep into the house, but was shot, and caught fire. Comrade Bulba opened the hatch, and shot three soldiers point blank. The rest panicked and fled. Comrade Bulba left the house and joined the infantry escort. With a rifle in hand, he continued pursuing the fleeing enemy. In this battle, comrade Bulba's tank destroyed 2 machine guns and up to 40 enemy infantrymen.

In combat for Peremoga, comrade Bulba once more courageously drove his tank into battle, and destroyed up to 35 enemy soldiers and officers. After his tank was damaged by an enemy shell, he managed to recover it from the battlefield. He is worthy of a government award, the Order of the Red Banner."

MS-1 Restoration

A while ago, I posted an article on the history of the MS-1, which mentioned that MS-1 tanks that exist today, survived as "legless" bunkers. Therefore, they no longer had original suspensions. Various MS-1s that are installed as monuments had their suspensions rebuilt, with mixed results. A reminder: the original suspension of the MS-1 looks like this.

LiveJournal user bf_109e took a photo of the following MS-1 in Vladivostok.

Well, uh, at least they tried. The garish green colour is, sadly, seen on a number of other monument tanks. The suspension is not even remotely similar to the original. Closer inspection reveals that it does not even have road wheels, only what appears to be a stamped metal bit with round ends. This MS-1 isn't going anywhere any time soon. The gun also suffered the restoration process (few MS-1 bunkers retained their original guns).

LJ user kamikadze1993 posted pictures of three MS-1s in Khabarovsk. The first one isn't that bad.

The number of shock absorbers and road wheels is correct. Something that appears to be torsion bars was added, but surely we can overlook such a minor detail, especially since the gun is a lot more reasonable and the colour isn't hideous.

Kind of primitive, but better than the first one! At least this one actually has wheels.

Aaaaahhh! What is this? And they couldn't even bother to put some sheet metal where the track covers used to be? How terrible. Although, maybe I can start some rumours of a Christie suspension MS-1...

But it only gets worse! This one is in an actual museum, at the Lenino-Snegiryev museum in Istra. 

The suspension isn't the worst so far, but some, er, liberties were taken with the rest of the tank. The cannon is where the machine guns should be and the commander's cupola looks like a pot.

And here is a unique example of an MS-1 in working order. This one is located in the Kubinka tank museum, and its suspension looks pretty decent.

The vehicle was found in parts, so it's hard to judge its condition, but the deficiency in the suspension is obvious even when the tank is not moving. The middle shock absorber is missing, and the road wheels are connected to a horizontal bar. This is even more obvious when the vehicle is in motion: not all of the road wheels rotate very well.

Mix and Match

The Soviet practice of making monuments out of military surplus is quite widespread. In nearly every town, no matter how small, there will be some kind of monument to the fighting that took place there, with a cannon or a tank. However, sometimes the tank on the monument is a mix and match of tank parts, some of which don't even belong on the same tank. For example, a photograph of a tank at Parfino (credit to LiveJournal user wadimych):

While a casual passerby might see nothing but a tank, an expert would swiftly detect an anomaly. Why, that's clearly a KV-1S turret on a KV-1 hull! What are they trying to pull here? However, upon further inspection, the plot thickens.

A German AT gunner made his mark here, with a shell that managed to strike the hull and turret, before bouncing off harmlessly. This means that this tank, as a whole, saw combat. But how could this be? The answer, as always, lies in the archives.

RGASPI 644-2-102

"Comrade Stalin

Comrade Molotov

By the order of the GKO, the Kirov factory has been producing KV-1S tanks that weigh 41.5-42 tons with improved components since August.

Due to the higher T-34 production quotas and cessation of shipments from factory #264 (Stalingrad), it was decided to increase the production of T-34 hulls at Uralmash and transfer the production of KV hulls to factory #200.

In September, factory #200 increased KV hull production nearly twofold. In order to match the plan, factory #200 needs to produce twice as many hulls in October as it did in September. 

Despite measures that were taken, the production is behind schedule. 

In order to meet the production quotas for KV tanks in October, I ask of you to allow the use of KV hulls with side armour thickness of 75 mm.

The GOKO decree is attached.

People's Commissar of Tank Manufacturing, I. Zaltsmann."

RGASPI 644-2-102

"The State Committee of Defense decrees that the Kirov factory is allowed to produce 100 KV tanks with thickened side armour (75 mm) to meet October quotas.

Chairman of the State Committee of Defense, Molotov"

In total, 70 of these hybrids were produced. 8 were sent to the 9th Guards Regiment at Kubinka, 16 to the 10th Guards Regiment at Kosterovo, 3 to the Ulyanov academy, 34 to the 12th Guards Regiment at Noginsk, 9 to the ZKU, and 7 to the Amoured Car and Tank Center at Lubertsy. The serial numbers of these vehicles are available in CAMD RF 38-11355-887, "Notice of accepted and sent KV-1S tanks with heavy KV-1 hulls".

IS-4 Start to Finish

The IS tank, released in 1943, had 120 mm of front armour, compared to its predecessor's 75, in roughly the same configuration. However, while the KV's 75 mm rendered it nearly invincible against all modern anti-tank guns, the IS did not have such luxury. Work on an IS tank with superior armour began during that same year.

"K" Heavy Tank, a precursor project to the IS-4.

CAMD RF 38-11355-2189

The above is a fragment of the blueprints of the first Object 701, with a clear date: December 1943. Sadly, Kirov factory must have been short on paper, as they used the backs of early 701 blueprints for scrap in 1944. 

Object 701 was a lofty goal indeed. It was designed to be impenetrable to the most powerful anti-tank guns of the day, the D-25 and KwK 43. As we've seen from a previous article, the tank eventually achieved that objective. However, early prototypes of the hull had a couple of weaknesses.

CAMD RF 38-11355-2411

"Photo #20. Penetration of the spherical cover of the TSh-17 sight with 88 mm armour piercing shells. Penetration of the driver's observation device with 88 mm shells.

Due to the spherical shape of the sight cover, a hit at a perpendicular angle, and therefore penetration, is possible at various angles. The rolled roof of the tank can be penetrated by 88 mm shells (see photo #19).

The cover of the driver's observation device can be penetrated by 88 mm shells (see photo #20). The factory used 8S steel, which cannot be properly conditioned when over 75 mm thick. Kirov factory representatives insist that use of this grade of steel was unavoidable.

The turret platform roof is penetrated by the shockwave of an HE-fragmentation 122 mm shell."

Well, the tank is mostly protected. Can't penetrate the upper glacis (shot 59 barely dents it), but the weak spots require a redesign. Let's look at how the rear armour fared.

CAMD RF 38-11355-2411

"Photo #9. Intact connections between the rear hull sides and hull rear, as well as the upper rear plate and lower rear plate after concentrated fire by 75 and 88 mm guns armour piercing shells."

Impressive! The guns cannot even penetrate the rear armour of the tank. The sides, however...

CAMD RF 38-11355-2411

"Photo #10. Rear side hull separated from the front side hull after welding seam was destroyed."

A lucky hit to the welding seam can penetrate the hull side, otherwise it performs very well. The tank's armour proves worthy, but the design of the hull needs some work. 

That was Object 701 #1. Objects 701 #2 and #3 had improved welding seams and higher hardening of the turret armour. The test results greatly improved as well: "The armour of the Object 701 tank provides complete protection from 75 and 88 mm shells with muzzle velocity of up to 1000 m/s at any distance, in an arc of +/- 60 degrees from the front of the hull and +/- 30 degrees from the front of the turret." As a result of these trials, the hull and turret designs of the Object 701 were accepted. Object 701 #5 and #6 later had the front plate increased to 140 mm to counter potential 105 and 128 mm guns.

The drivetrain needed some work, though. Object 701 #4 received an improved transmission, which was further improved in #5 and #6 prototypes.

As for the armament, the gun was the same old D-25 that has proven itself against the toughest German armour. 

"According to your requests, the Chebarkul GAU proving grounds tested the 122 mm tank gun model 1943 (D-25) in the new heavy tank (object 701), developed by the Kirov factory, between May 11th and 15th of 1945. 

In total, 403 shots were fired. The trials established that:

1. The precision of the gun at 500, 1000, and 2000 meters is satisfactory.
2. The angle of incidence of AP and HE shells is the same, -2.9 minutes, nearly identical to the calculated angle (-3 minutes).
3. The practical rate of fire is 2-3 RPM, and peak is 3-4 RPM.
   The main complaints in the process of trials were about the fighting compartment equipment and gun installation.
1. The three propellant casing holder on the right side of the turret is impeded by the signal flare box and machine gun ammunition box.
2. The elevation mechanism carrier was crooked.

After the removal of the above deficiencies, especially after increasing the robustness of the elevation mechanism carrier, trials as to be repeated.

The 122 mm tank gun trialled in May of 1945 was produced in April-May of 1944. After that, the gun was substantially modified and improved. Most importantly, the gun's semi-automatics were improved, removing the possibility of breaking the breech opening roller pin. All other downsides of the gun can be explained by quality of production

Deputy chair of the AK GAU KA, Major-General of the Artillery Engineering Service, Zhevanik"

One of the modifications to the gun in that time must have been Kotin's loading assistance device, which increased the peak rate of fire on the IS-2 to 6 rounds per minute. 

However, May 1945 marked the defeat of Germany. Fighting the Japanese would not require a powerful new tank, and it was unclear what it would be used for, if anything. Engineers and equipment was needed for peacetime duties. Here are some excerpts from a Kirov factory report for the first quarter of 1946.

"All the best and most precise equipment was moved from tank-building plants to tractor building plants.

...

The remaining equipment is from before the War, and did not have proper service since then, and therefore, 40% of it requires medium or major repairs. 

...

The best tank engineers, plant managers, technologists, foremen, and highly qualified employees were transferred to tractor production. For example: out of 212 tank engineers, 112 remained by January 1st, 1945, and 66 remain as of January 1st, 1946. The 146 employees were transferred to other positions, including managers and production line foremen.

The remaining 66 engineers perform the following duties. 16 engineers develop new objects, while 50 of the less qualified engineers work on Object 701 and production of the IS-3 tank. 

This is insufficient for preparation of the 701st for production. The number must be increased to 100 engineers. 

...

There used to be 470 controllers and 7839 employees in the 11 tank building plants as of June 1st, 1945. These numbers are now reduced to 5 plants, 198 controllers, and 3358 employees. 

The employees are new, and had to familiarize themselves with the new technologies in April-May, leading to lower quality of joints and installations of IS-3 components. "

CAMD RF 38-11355-3130

The IS-4 was cancelled after production of just over 250 units. The heavily armoured sluggish behemoth of old was incompatible with the modern maneuverable war, especially with the looming threat of nuclear escalation.